QChem currently has more than 30 exchange functionals as well as more than 30 correlation functionals, and in addition over 150 exchangecorrelation (XC) functionals, which refer to functionals that are not separated into exchange and correlation parts, either because the way in which they were parameterized renders such a separation meaningless (e.g., B97D[Grimme(2006b)] or B97X[Chai and HeadGordon(2008a)]) or because they are a standard linear combination of exchange and correlation (e.g., PBE[Perdew et al.(1996)Perdew, Burke, and Ernzerhof] or B3LYP[Becke(1993), Stephens et al.(1994)Stephens, Devlin, Chabolowski, and Frisch]). Userdefined XC functionals can be created as specified linear combinations of any of the 30+ exchange functionals and/or the 30+ correlation functionals.
KSDFT functionals can be organized onto a ladder with five rungs, in a classification scheme (“Jacob’s Ladder”) proposed by John Perdew[Perdew et al.(2005)Perdew, Ruzsinszky, Tao, Staroverov, Scuseria, and Csonka] in 2001. The first rung contains a functional that only depends on the (spin)density , namely, the local spindensity approximation (LSDA). These functionals are exact for the infinite uniform electron gas (UEG), but are highly inaccurate for molecular properties whose densities exhibit significant inhomogeneity. To improve upon the weaknesses of the LSDA, it is necessary to introduce an ingredient that can account for inhomogeneities in the density: the density gradient, . These generalized gradient approximation (GGA) functionals define the second rung of Jacob’s Ladder and tend to improve significantly upon the LSDA. Two additional ingredients that can be used to further improve the performance of GGA functionals are either the Laplacian of the density , and/or the kinetic energy density,
(5.17) 
While functionals that employ both of these options are available in QChem, the kinetic energy density is by far the more popular ingredient and has been used in many modern functionals to add flexibility to the functional form with respect to both constraint satisfaction (nonempirical functionals) and leastsquares fitting (semiempirical parameterization). Functionals that depend on either of these two ingredients belong to the third rung of the Jacob’s Ladder and are called metaGGAs. These metaGGAs often further improve upon GGAs in areas such as thermochemistry, kinetics (reaction barrier heights), and even noncovalent interactions.
Functionals on the fourth rung of Jacob’s Ladder are called hybrid density functionals. This rung contains arguably the most popular density functional of our time, B3LYP, the first functional to see widespread application in chemistry. “Global” hybrid (GH) functionals such as B3LYP (as distinguished from the “rangeseparated hybrids" introduced below) add a constant fraction of “exact” (HartreeFock) exchange to any of the functionals from the first three rungs. Thus, hybrid LSDA, hybrid GGA, and hybrid metaGGA functionals can be constructed, although the latter two types are much more common. As an example, the formula for the B3LYP functional, as implemented in QChem, is
(5.18) 
where , , and .
A more recent approach to introducing exact exchange into the functional form is via range separation. Rangeseparated hybrid (RSH) functionals split the exact exchange contribution into a shortrange (SR) component and a longrange (LR) component, often by means of the error function (erf) and complementary error function ():
(5.19) 
The first term on the right in Eq. () is singular but shortrange, and decays to zero on a length scale of , while the second term constitutes a nonsingular, longrange background. An RSH XC functional can be expressed generically as
(5.20) 
where the SR and LR parts of the Coulomb operator are used, respectively, to evaluate the HF exchange energies and . The corresponding DFT exchange functional is partitioned in the same manner, but the correlation energy is evaluated using the full Coulomb operator, . Of the two linear parameters in Eq. eq:RSHGGA, is usually either set to 1 to define longrange corrected (LRC) RSH functionals (see Section 5.6) or else set to 0, which defines screenedexchange (SE) RSH functionals. On the other hand, the fraction of shortrange exact exchange () can either be determined via leastsquares fitting, theoretically justified using the adiabatic connection, or simply set to zero. As with the global hybrids, RSH functionals can be fashioned using all of the ingredients from the lower three rungs. The rate at which the local DFT exchange is turned off and the nonlocal exact exchange is turned on is controlled by the parameter . Large values of tend to lead to attenuators that are less smooth (unless the fraction of shortrange exact exchange is very large), while small values of (e.g., 0.2–0.3 bohr) are the most common in semiempirical RSH functionals.
The final rung on Jacob’s Ladder contains functionals that use not only occupied orbitals (via exact exchange), but virtual orbitals as well (via methods such as MP2 or the random phase approximation, RPA). These double hybrids (DH) are the most expensive density functionals available in QChem, but can also be very accurate. The most basic form of a DH functional is
(5.21) 
As with hybrids, the coefficients can either be theoretically motivated or empirically determined. In addition, double hybrids can use exact exchange both globally or via rangeseparation, and their components can be as primitive as LSDA or as advanced as in metaGGA functionals. More information on double hybrids can be found in Section 5.9.
Finally, the last major advance in KSDFT in recent years has been the development of methods that are capable of accurately describing noncovalent interactions, particularly dispersion. All of the functionals from Jacob’s Ladder can technically be combined with these dispersion corrections, although in some cases the combination is detrimental, particularly for semiempirical functionals that were parameterized in part using data sets of noncovalent interactions, and already tend to overestimate noncovalent interaction energies. The most popular such methods available in QChem are:
Nonlocal correlation (NLC) functionals (Section 5.7.1), including those of Vydrov and Van Voorhis[Vydrov and Van Voorhis(2009), Vydrov and Van Voorhis(2010b)] (VV09 and VV10) and of Lundqvist and Langreth[Dion et al.(2004)Dion, Rydberg, Schröder, Langreth, and Lundqvist, Dion et al.(2005)Dion, Rydberg, Schröder, Langreth, and Lundqvist] (vdWDF04 and vdWDF10). The revised VV10 NLC functional of Sabatini and coworkers (rVV10) is also available[Sabatini et al.(2013)Sabatini, Gorni, and de Gironcoli].
Damped, atom–atom pairwise empirical dispersion potentials from Grimme and others[Grimme(2006b), Chai and HeadGordon(2008b), Grimme et al.(2010)Grimme, Antony, Ehrlich, and Krieg, Grimme et al.(2011)Grimme, Ehrlich, and Goerigk, Schröder et al.(2015)Schröder, Creon, and Schwabe, Smith et al.(2016)Smith, Burns, Patkowski, and Sherrill] [DFTD2, DFTCHG, DFTD3(0), DFTD3(BJ), DFTD3(CSO), DFTD3M(0), DFTD3M(BJ), and DFTD3(op)]; see Section 5.7.2.
The exchangedipole models (XDM) of Johnson and Becke (XDM6 and XDM10); see Section 5.7.3.
The Tkatchenko and Scheffler (TS) method for dispersion interactions[Tkatchenko and Scheffler(2009)]; see Section 5.7.4.
The ManyBody Dispersion (MBD) method for van der Waals interactions[Tkatchenko et al.(2012)Tkatchenko, DiStasio, Jr., Car, and Scheffler, Ambrosetti et al.(2014)Ambrosetti, Reilly, DiStasio, Jr., and Tkatchenko]; see Section 5.7.5.
Below, we categorize the functionals that are available in QChem, including exchange functionals (Section 5.3.2), correlation functionals (Section 5.3.3), and exchangecorrelation functionals (Section 5.3.4). Within each category the functionals will be categorized according to Jacob’s Ladder. Exchange and correlation functionals can be invoked using the $rem variables EXCHANGE and CORRELATION, while the exchangecorrelation functionals can be invoked either by setting the $rem variable METHOD or alternatively (in most cases, and for backwards compatibility with earlier versions of QChem) by using the $rem variable EXCHANGE. Some caution is warranted here. While setting METHOD to PBE, for example, requests the PerdewBurkeErnzerhof (PBE) exchangecorrelation functional,[Perdew et al.(1996)Perdew, Burke, and Ernzerhof] which includes both PBE exchange and PBE correlation, setting EXCHANGE = PBE requests only the exchange component and setting CORRELATION = PBE requests only the correlation component. Setting both of these values is equivalent to specifying METHOD = PBE.
SinglePoint 
Optimization 
Frequency 

Ground State 
LSDA 
LSDA 
LSDA 
GGA 
GGA 
GGA 

metaGGA 
metaGGA 
— 

GH 
GH 
GH 

RSH 
RSH 
RSH 

NLC 
NLC 
— 

DFTD 
DFTD 
DFTD 

XDM 
— 
— 

TDDFT 
LSDA 
LSDA 
LSDA 
GGA 
GGA 
GGA 

metaGGA 
— 
— 

GH 
GH 
GH 

RSH 
RSH 
— 

— 
— 
— 

DFTD 
DFTD 
DFTD 

— 
— 
— 

OpenMP parallelization available 

MPI parallelization available 
Finally, Table 5.1 provides a summary, arranged according to Jacob’s Ladder, of which categories of functionals are available with analytic first derivatives (for geometry optimizations) or second derivatives (for vibrational frequency calculations). If analytic derivatives are not available for the requested job type, QChem will automatically generate them via finite difference. Tests of the finitedifference procedure, in cases where analytic second derivatives are available, suggest that finitedifference frequencies are accurate to cm, except for very lowfrequency, nonbonded modes.[Liu et al.(2017)Liu, Liu, and Herbert] Also listed in Table 5.1 are which functionals are available for excitedstate timedependent DFT (TDDFT) calculations, as described in Section 7.3. Lastly, Table 5.1 describes which functionals have been parallelized with OpenMP and/or MPI.
QChem contains over 150 exchangecorrelation functionals, not counting those that can be straightforwardly appended with a dispersion correction (such as B3LYPD3). Therefore, we suggest a few functionals from the second through fourth rungs of Jacob’s Ladder in order to guide functional selection. Most of these suggestions come from a benchmark of over 200 density functionals on a vast database of nearly 5000 data points, covering noncovalent interactions, isomerization energies, thermochemistry, and barrier heights. The single recommended method from each category is indicated in bold.
From the GGAs on Rung 2, we recommend:
B97D3(BJ) – METHOD B97D3 and DFT_D D3_BJ
revPBED3(BJ) – METHOD revPBE and DFT_D D3_BJ
BLYPD3(BJ) – METHOD BLYP and DFT_D D3_BJ
PBE – METHOD PBE
From the metaGGAs on Rung 3, we recommend:
B97MrV – METHOD B97MrV
MS1D3(0) – METHOD MS1 and DFT_D D3_ZERO
MS2D3(0) – METHOD MS2 and DFT_D D3_ZERO
M06LD3(0) – METHOD M06L and DFT_D D3_ZERO
TPSSD3(BJ) – METHOD TPSS and DFT_D D3_BJ
From the hybrid GGAs on Rung 4, we recommend:
B97XV – METHOD wB97XV
B97XD3 – METHOD wB97XD3
B97XD – METHOD wB97XD
B3LYPD3(BJ) – METHOD B3LYP and DFT_D D3_BJ
revPBE0D3(BJ) – METHOD revPBE0 and DFT_D D3_BJ
From the hybrid metaGGAs on Rung 4, we recommend:
B97MV – METHOD wB97MV
M05D – METHOD wM05D
M062XD3(0) – METHOD M062X and DFT_D D3_ZERO
TPSShD3(BJ) – METHOD TPSSh and DFT_D D3_BJ
Note: All exchange functionals in this section can be invoked using the $rem variable EXCHANGE. Popular and/or recommended functionals within each class are listed first and indicated in bold. The rest are in alphabetical order.
Local SpinDensity Approximation (LSDA)
Slater – SlaterDirac exchange functional (X method with )[Dirac(1930)]
SR_LSDA (BNL) – Shortrange version of the SlaterDirac exchange functional[Gill et al.(1996)Gill, Adamson, and Pople]
Generalized Gradient Approximation (GGA)
PBE – Perdew, Burke, and Ernzerhof exchange functional[Perdew et al.(1996)Perdew, Burke, and Ernzerhof]
B88 – Becke exchange functional from 1988[Becke(1988b)]
revPBE – Zhang and Yang oneparameter modification of the PBE exchange functional[Zhang and Yang(1998)]
AK13 – ArmientoKümmel exchange functional from 2013[Armiento and Kümmel(2013)]
B86 – Becke exchange functional (X) from 1986[Becke(1986a)]
G96 – Gill exchange functional from 1996[Gill(1996)]
mB86 – Becke “modified gradient correction” exchange functional from 1986[Becke(1986b)]
mPW91 – modified version (Adamo and Barone) of the 1991 PerdewWang exchange functional[Adamo and Barone(1998)]
muB88 (B88) – Shortrange version of the B88 exchange functional by Hirao and coworkers[Iikura et al.(2001)Iikura, Tsuneda, Yanai, and Hirao]
muPBE (PBE) – Shortrange version of the PBE exchange functional by Hirao and coworkers[Iikura et al.(2001)Iikura, Tsuneda, Yanai, and Hirao]
optB88 – Refit version of the original B88 exchange functional (for use with vdWDF04) by Michaelides and coworkers[Klimeš et al.(2010)Klimeš, Bowler, and Michaelides]
OPTX – Twoparameter exchange functional by Handy and Cohen[Handy and Cohen(2001)]
PBEsol – PBE exchange functional modified for solids[Perdew et al.(2008a)Perdew, Ruzsinszky, Csonka, Vydrov, Scuseria, Constantin, Zhou, and Burke]
PW86 – PerdewWang exchange functional from 1986[Perdew and Wang(1986)]
PW91 – PerdewWang exchange functional from 1991[Perdew et al.(1992)Perdew, Chevary, Vosko, Jackson, Pederson, Singh, and Fiolhais]
RPBE – Hammer, Hansen, and Norskov exchange functional (modification of PBE)[Hammer et al.(1999)Hammer, Hansen, and Nørskov]
rPW86 – Revised version (Murray et al.) of the 1986 PerdewWang exchange functional[Murray et al.(2009)Murray, Lee, and Langreth]
SOGGA – Secondorder GGA functional by Zhao and Truhlar[Zhao and Truhlar(2006c)]
wPBE (PBE) – Henderson et al. model for the PBE GGA shortrange exchange hole[Henderson et al.(2008)Henderson, Janesko, and Scuseria]
MetaGeneralized Gradient Approximation (metaGGA)
TPSS – Tao, Perdew, Staroverov, and Scuseria exchange functional[Tao et al.(2003)Tao, Perdew, Staroverov, and Scuseria]
revTPSS – Revised version of the TPSS exchange functional[Perdew et al.(2009)Perdew, Ruzsinszky, Csonka, Constantin, and Sun]
BLOC – Minor modification of the TPSS exchange functional that works best with TPSSloc correlation (both by Della Sala and coworkers)[Constantin et al.(2013)Constantin, Fabiano, and Sala]
modTPSS – Oneparameter version of the TPSS exchange functional[Perdew et al.(2007)Perdew, Ruzsinszky, Tao, Csonka, and Scuseria]
oTPSS – TPSS exchange functional with 5 refit parameters (for use with oTPSS correlation) by Grimme and coworkers[Goerigk and Grimme(2010)]
PBEGX – First exchange functional based on a finite uniform electron gas (rather than an infinite UEG) by PierreFrançois Loos[Loos(2017)]
PKZB – Perdew, Kurth, Zupan, and Blaha exchange functional[Perdew et al.(1999)Perdew, Kurth, Zupan, and Blaha]
regTPSS – Regularized (fixed order of limits issue) version of the TPSS exchange functional[Ruzsinszky et al.(2012)Ruzsinszky, Sun, Xiao, and Csonka]
SCAN – Strongly Constrained and Appropriately Normed exchange functional[Sun et al.(2015b)Sun, Ruzsinszky, and Perdew]
TM – TaoMo exchange functional derived via an accurate modeling of the conventional exchange hole[Tao and Mo(2016)]
Note: All correlation functionals in this section can be invoked using the $rem variable CORRELATION. Popular and/or recommended functionals within each class are listed first and indicated in bold. The rest are in alphabetical order.
Local SpinDensity Approximation (LSDA)
PW92 – PerdewWang parameterization of the LSDA correlation energy from 1992[Perdew and Wang(1992)]
VWN5 (VWN) – VoskoWilkNusair parameterization of the LSDA correlation energy #5[Vosko et al.(1980)Vosko, Wilk, and Nusair]
LiuParr – LiuParr model from the functional expansion formulation[Liu and Parr(2000)]
PK09 – ProynovKong parameterization of the LSDA correlation energy from 2009[Proynov and Kong(2009)]
PW92RPA – PerdewWang parameterization of the LSDA correlation energy from 1992 with RPA values[Perdew and Wang(1992)]
PZ81 – PerdewZunger parameterization of the LSDA correlation energy from 1981[Perdew and Zunger(1981)]
VWN1 – VoskoWilkNusair parameterization of the LSDA correlation energy #1[Vosko et al.(1980)Vosko, Wilk, and Nusair]
VWN1RPA – VoskoWilkNusair parameterization of the LSDA correlation energy #1 with RPA values[Vosko et al.(1980)Vosko, Wilk, and Nusair]
VWN2 – VoskoWilkNusair parameterization of the LSDA correlation energy #2[Vosko et al.(1980)Vosko, Wilk, and Nusair]
VWN3 – VoskoWilkNusair parameterization of the LSDA correlation energy #3[Vosko et al.(1980)Vosko, Wilk, and Nusair]
VWN4 – VoskoWilkNusair parameterization of the LSDA correlation energy #4[Vosko et al.(1980)Vosko, Wilk, and Nusair]
Wigner – Wigner correlation functional (simplification of LYP)[Wigner(1938), Stewart and Gill(1995)]
Generalized Gradient Approximation (GGA)
PBE – Perdew, Burke, and Ernzerhof correlation functional[Perdew et al.(1996)Perdew, Burke, and Ernzerhof]
LYP – LeeYangParr oppositespin correlation functional[Lee et al.(1988)Lee, Yang, and Parr]
P86 – PerdewWang correlation functional from 1986 based on the PZ81 LSDA functional[Perdew(1986)]
P86VWN5 – PerdewWang correlation functional from 1986 based on the VWN5 LSDA functional[Perdew(1986)]
PBEloc – PBE correlation functional with a modified beta term by Della Sala and coworkers[Constantin et al.(2012)Constantin, Fabiano, and Sala]
PBEsol – PBE correlation functional modified for solids[Perdew et al.(2008a)Perdew, Ruzsinszky, Csonka, Vydrov, Scuseria, Constantin, Zhou, and Burke]
PW91 – PerdewWang correlation functional from 1991[Perdew et al.(1992)Perdew, Chevary, Vosko, Jackson, Pederson, Singh, and Fiolhais]
regTPSS – Slight modification of the PBE correlation functional (also called vPBEc)[Ruzsinszky et al.(2012)Ruzsinszky, Sun, Xiao, and Csonka]
MetaGeneralized Gradient Approximation (metaGGA)
TPSS – Tao, Perdew, Staroverov, and Scuseria correlation functional[Tao et al.(2003)Tao, Perdew, Staroverov, and Scuseria]
revTPSS – Revised version of the TPSS correlation functional[Perdew et al.(2009)Perdew, Ruzsinszky, Csonka, Constantin, and Sun]
B95 – Becke’s twoparameter correlation functional from 1995[Becke(1996)]
oTPSS – TPSS correlation functional with 2 refit parameters (for use with oTPSS exchange) by Grimme and coworkers[Goerigk and Grimme(2010)]
PK06 – ProynovKong “tLap” functional with and Laplacian dependence[Proynov and Kong(2007)]
PKZB – Perdew, Kurth, Zupan, and Blaha correlation functional[Perdew et al.(1999)Perdew, Kurth, Zupan, and Blaha]
SCAN – Strongly Constrained and Appropriately Normed correlation functional[Sun et al.(2015b)Sun, Ruzsinszky, and Perdew]
TM – TaoMo correlation functional, representing a minor modification to the TPSS correlation functional[Tao and Mo(2016)]
TPSSloc – The TPSS correlation functional with the PBE component replaced by the PBEloc correlation functional[Constantin et al.(2012)Constantin, Fabiano, and Sala]
Note: All exchangecorrelation functionals in this section can be invoked using the $rem variable METHOD. For backwards compatibility, all of the exchangecorrelation functionals except for the ones marked with an asterisk can be used with the $rem variable EXCHANGE. Popular and/or recommended functionals within each class are listed first and indicated in bold. The rest are in alphabetical order.
Local SpinDensity Approximation (LSDA)
SPW92* – Slater LSDA exchange + PW92 LSDA correlation
LDA – Slater LSDA exchange + VWN5 LSDA correlation
SVWN5* – Slater LSDA exchange + VWN5 LSDA correlation
Generalized Gradient Approximation (GGA)
B97D3(0) – B97D with a fitted DFTD3(0) tail instead of the original DFTD2 tail[Grimme et al.(2010)Grimme, Antony, Ehrlich, and Krieg]
B97D – 9parameter dispersioncorrected (DFTD2) functional by Grimme[Grimme(2006b)]
PBE* – PBE GGA exchange + PBE GGA correlation
BLYP* – B88 GGA exchange + LYP GGA correlation
revPBE* – revPBE GGA exchange + PBE GGA correlation
BEEFvdW – 31parameter semiempirical exchange functional developed via a Bayesian error estimation framework paired with PBE correlation and vdWDF10 NLC[Wellendorff et al.(2012)Wellendorff, Lundgaard, Møgelhøj, Petzold, Landis, Nørskov, Bligaard, and Jacobsen]
BOP – B88 GGA exchange + BOP “oneparameter progressive” GGA correlation[Tsuneda et al.(1999)Tsuneda, Suzumura, and Hirao]
BP86* – B88 GGA exchange + P86 GGA correlation
BP86VWN* – B88 GGA exchange + P86VWN5 GGA correlation
BPBE* – B88 GGA exchange + PBE GGA correlation
EDF1 – Modification of BLYP to give good performance in the 631+G* basis set[Adamson et al.(1998)Adamson, Gill, and Pople]
EDF2 – Modification of B3LYP to give good performance in the ccpVTZ basis set for frequencies[Lin et al.(2004)Lin, George, and Gill]
GAM – 21parameter nonseparable gradient approximation functional by Truhlar and coworkers[Yu et al.(2015)Yu, Zhang, Verma, He, and Truhlar]
HCTH93 (HCTH/93) – 15parameter functional trained on 93 systems by Handy and coworkers[Hamprecht et al.(1998)Hamprecht, Cohen, Tozer, and Handy]
HCTH120 (HCTH/120) – 15parameter functional trained on 120 systems by Boese et al.[Boese et al.(2000)Boese, Doltsinis, Handy, and Sprik]
HCTH147 (HCTH/147) – 15parameter functional trained on 147 systems by Boese et al.[Boese et al.(2000)Boese, Doltsinis, Handy, and Sprik]
HCTH407 (HCTH/407) – 15parameter functional trained on 407 systems by Boese and Handy[Boese and Handy(2001)]
HLE16 – HCTH/407 exchange functional enhanced by a factor of 1.25 + HCTH/407 correlation functional enhanced by a factor of 0.5[Verma and Truhlar(2017)]
KT1 – GGA functional designed specifically for shielding constant calculations[Keal and Tozer(2003)]
KT2 – GGA functional designed specifically for shielding constant calculations[Keal and Tozer(2003)]
KT3 – GGA functional with improved results for maingroup nuclear magnetic resonance shielding constants[Keal and Tozer(2004)]
mPW91* – mPW91 GGA exchange + PW91 GGA correlation
N12 – 21parameter nonseparable gradient approximation functional by Peverati and Truhlar[Peverati and Truhlar(2012b)]
OLYP* – OPTX GGA exchange + LYP GGA correlation
PBEOP – PBE GGA exchange + PBEOP “oneparameter progressive” GGA correlation[Tsuneda et al.(1999)Tsuneda, Suzumura, and Hirao]
PBEsol* – PBEsol GGA exchange + PBEsol GGA correlation
PW91* – PW91 GGA exchange + PW91 GGA correlation
RPBE* – RPBE GGA exchange + PBE GGA correlation
rVV10* – rPW86 GGA exchange + PBE GGA correlation + rVV10 nonlocal correlation[Sabatini et al.(2013)Sabatini, Gorni, and de Gironcoli]
SOGGA* – SOGGA GGA exchange + PBE GGA correlation
SOGGA11 – 20parameter functional by Peverati, Zhao, and Truhlar[Peverati et al.(2011)Peverati, Zhao, and Truhlar]
VV10 – rPW86 GGA exchange + PBE GGA correlation + VV10 nonlocal correlation[Vydrov and Van Voorhis(2010b)]
MetaGeneralized Gradient Approximation (metaGGA)
B97MV – 12parameter combinatoriallyoptimized, dispersioncorrected (VV10) functional by Mardirossian and HeadGordon[Mardirossian and HeadGordon(2015)]
B97MrV* – B97MV density functional with the VV10 NLC functional replaced by the rVV10 NLC functional[Mardirossian et al.(2017)Mardirossian, Pestana, Womack, Skylaris, HeadGordon, and HeadGordon]
M06L – 34parameter functional by Zhao and Truhlar[Zhao and Truhlar(2006a)]
TPSS* – TPSS metaGGA exchange + TPSS metaGGA correlation
revTPSS* – revTPSS metaGGA exchange + revTPSS metaGGA correlation
BLOC* – BLOC metaGGA exchange + TPSSloc metaGGA correlation
M11L – 44parameter dualrange functional by Peverati and Truhlar[Peverati and Truhlar(2012a)]
mBEEF – 64parameter exchange functional paired with the PBEsol correlation functional[Wellendorff et al.(2014)Wellendorff, Lundgaard, Jacobsen, and Bligaard]
MGGA_MS0 – MGGA_MS0 metaGGA exchange + regTPSS GGA correlation[Sun et al.(2012)Sun, Xiao, and Ruzsinszky]
MGGA_MS1 – MGGA_MS1 metaGGA exchange + regTPSS GGA correlation[Sun et al.(2013)Sun, Haunschild, Xiao, Bulik, Scuseria, and Perdew]
MGGA_MS2 – MGGA_MS2 metaGGA exchange + regTPSS GGA correlation[Sun et al.(2013)Sun, Haunschild, Xiao, Bulik, Scuseria, and Perdew]
MGGA_MVS – MGGA_MVS metaGGA exchange + regTPSS GGA correlation[Sun et al.(2015a)Sun, Perdew, and Ruzsinszky]
MN12L – 58parameter metanonseparable gradient approximation functional by Peverati and Truhlar[Peverati and Truhlar(2012c)]
MN15L – 58parameter metanonseparable gradient approximation functional by Yu, He, and Truhlar[Yu et al.(2016b)Yu, He, and Truhlar]
oTPSS* – oTPSS metaGGA exchange + oTPSS metaGGA correlation
PKZB* – PKZB metaGGA exchange + PKZB metaGGA correlation
SCAN* – SCAN metaGGA exchange + SCAN metaGGA correlation
tHCTH (HCTH) – 16parameter functional by Boese and Handy[Boese and Handy(2002)]
TM* – TM metaGGA exchange + TM metaGGA correlation[Tao and Mo(2016)]
VSXC – 21parameter functional by Voorhis and Scuseria[Van Voorhis and Scuseria(1998)]
Global Hybrid Generalized Gradient Approximation (GH GGA)
B3LYP – 20% HF exchange + 8% Slater LSDA exchange + 72% B88 GGA exchange + 19% VWN1RPA LSDA correlation + 81% LYP GGA correlation[Becke(1993), Stephens et al.(1994)Stephens, Devlin, Chabolowski, and Frisch]
PBE0 – 25% HF exchange + 75% PBE GGA exchange + PBE GGA correlation[Adamo and Barone(1999)]
revPBE0 – 25% HF exchange + 75% revPBE GGA exchange + PBE GGA correlation
B97 – Becke’s original 10parameter density functional with 19.43% HF exchange[Becke(1997)]
B1LYP – 25% HF exchange + 75% B88 GGA exchange + LYP GGA correlation[Adamo and Barone(1997)]
B1PW91 – 25% HF exchange + 75% B88 GGA exchange + PW91 GGA correlation[Adamo and Barone(1997)]
B3LYP5 – 20% HF exchange + 8% Slater LSDA exchange + 72% B88 GGA exchange + 19% VWN5 LSDA correlation + 81% LYP GGA correlation[Becke(1993), Stephens et al.(1994)Stephens, Devlin, Chabolowski, and Frisch]
B3P86 – 20% HF exchange + 8% Slater LSDA exchange + 72% B88 GGA exchange+ 19% VWN1RPA LSDA correlation + 81% P86 GGA correlation
B1LYP – 25% HF exchange + 75% B88 GGA exchange + LYP GGA correlation[Adamo and Barone(1997)]
B1PW91 – 25% HF exchange + 75% B88 GGA exchange + PW91 GGA correlation[Adamo and Barone(1997)]
B3LYP5 – 20% HF exchange + 8% Slater LSDA exchange + 72% B88 GGA exchange + 19% VWN5 LSDA correlation + 81% LYP GGA correlation[Becke(1993), Stephens et al.(1994)Stephens, Devlin, Chabolowski, and Frisch]
B3P86 – 20% HF exchange + 8% Slater LSDA exchange + 72% B88 GGA exchange+ 19% VWN1RPA LSDA correlation + 81% P86 GGA correlation
B3PW91 – 20% HF exchange + 8% Slater LSDA exchange + 72% B88 GGA exchange+ 19% PW92 LSDA correlation + 81% PW91 GGA correlation[Becke(1993)]
B5050LYP – 50% HF exchange + 8% Slater LSDA exchange + 42% B88 GGA exchange + 19% VWN5 LSDA correlation + 81% LYP GGA correlation[Shao et al.(2003)Shao, HeadGordon, and Krylov]
B971 – Selfconsistent parameterization of Becke’s B97 density functional with 21% HF exchange[Hamprecht et al.(1998)Hamprecht, Cohen, Tozer, and Handy]
B972 – Reparameterization of B97 by Tozer and coworkers with 21% HF exchange[Wilson et al.(2001)Wilson, Bradley, and Tozer]
B973 – 16parameter version of B97 by Keal and Tozer with 26.93% HF exchange[Keal and Tozer(2005)]
B97K – Reparameterization of B97 for kinetics by Boese and Martin with 42% HF exchange[Boese and Martin(2004)]
BHHLYP – 50% HF exchange + 50% B88 GGA exchange + LYP GGA correlation
HFLYP* – 100% HF exchange + LYP GGA correlation
MPW1K – 42.8% HF exchange + 57.2% mPW91 GGA exchange + PW91 GGA correlation[Lynch et al.(2000)Lynch, Fast, Harris, and Truhlar]
MPW1LYP – 25% HF exchange + 75% mPW91 GGA exchange + LYP GGA correlation[Adamo and Barone(1998)]
MPW1PBE – 25% HF exchange + 75% mPW91 GGA exchange + PBE GGA correlation[Adamo and Barone(1998)]
MPW1PW91 – 25% HF exchange + 75% mPW91 GGA exchange + PW91 GGA correlation[Adamo and Barone(1998)]
O3LYP – 11.61% HF exchange + 7.1% Slater LSDA exchange + 81.33% OPTX GGA exchange + 19% VWN5 LSDA correlation + 81% LYP GGA correlation[Hoe et al.(2001)Hoe, Cohen, and Handy]
PBEh3c – Lowcost composite scheme of Grimme and coworkers for use with the def2mSVP basis set only[Grimme et al.(2015)Grimme, Brandenburg, Bannwarth, and Hansen]
PBE50 – 50% HF exchange + 50% PBE GGA exchange + PBE GGA correlation[Bernard et al.(2012b)Bernard, Shao, and Krylov]
SOGGA11X – 21parameter functional with 40.15% HF exchange by Peverati and Truhlar[Peverati and Truhlar(2011a)]
WC04 – Hybrid density functional optimized for the computation of C chemical shifts[Wiitala et al.(2006)Wiitala, Hoye, and Cramer]
WP04 – Hybrid density functional optimized for the computation of H chemical shifts[Wiitala et al.(2006)Wiitala, Hoye, and Cramer]
X3LYP – 21.8% HF exchange + 7.3% Slater LSDA exchange + 54.24% B88 GGA exchange + 16.66% PW91 GGA exchange + 12.9% VWN1RPA LSDA correlation + 87.1% LYP GGA correlation[Xu and Goddard III(2004)]
Global Hybrid MetaGeneralized Gradient Approximation (GH metaGGA)
M062X – 29parameter functional with 54% HF exchange by Zhao and Truhlar[Zhao and Truhlar(2008)]
M08HX – 47parameter functional with 52.23% HF exchange by Zhao and Truhlar[Zhao and Truhlar(2007)]
TPSSh – 10% HF exchange + 90% TPSS metaGGA exchange + TPSS metaGGA correlation[Staroverov et al.(2003)Staroverov, Scuseria, Tao, and Perdew]
revTPSSh – 10% HF exchange + 90% revTPSS metaGGA exchange + revTPSS metaGGA correlation[Csonka et al.(2010)Csonka, Perdew, and Ruzsinszky]
B1B95 – 28% HF exchange + 72% B88 GGA exchange + B95 metaGGA correlation[Becke(1996)]
B3TLAP – 17.13% HF exchange + 9.66% Slater LSDA exchange + 72.6% B88 GGA exchange + PK06 metaGGA correlation[Proynov and Kong(2007), Proynov and Kong(2008)]
BB1K – 42% HF exchange + 58% B88 GGA exchange + B95 metaGGA correlation[Zhao et al.(2004)Zhao, Lynch, and Truhlar]
BMK – BoeseMartin functional for kinetics with 42% HF exchange[Boese and Martin(2004)]
dlDF – Dispersionless density functional (based on the M052X functional form) by Szalewicz and coworkers[Pernal et al.(2009)Pernal, Podeszwa, Patkowski, and Szalewicz]
M05 – 22parameter functional with 28% HF exchange by Zhao, Schultz, and Truhlar[Zhao et al.(2005)Zhao, Schultz, and Truhlar]
M052X – 19parameter functional with 56% HF exchange by Zhao, Schultz, and Truhlar[Zhao et al.(2006)Zhao, Schultz, and Truhlar]
M06 – 33parameter functional with 27% HF exchange by Zhao and Truhlar[Zhao and Truhlar(2008)]
M06HF – 32parameter functional with 100% HF exchange by Zhao and Truhlar[Zhao and Truhlar(2006b)]
M08SO – 44parameter functional with 56.79% HF exchange by Zhao and Truhlar[Zhao and Truhlar(2007)]
MGGA_MS2h – 9% HF exchange + 91 % MGGA_MS2 metaGGA exchange + regTPSS GGA correlation[Sun et al.(2013)Sun, Haunschild, Xiao, Bulik, Scuseria, and Perdew]
MGGA_MVSh – 25% HF exchange + 75 % MGGA_MVS metaGGA exchange + regTPSS GGA correlation[Sun et al.(2015a)Sun, Perdew, and Ruzsinszky]
MN15 – 59parameter functional with 44% HF exchange by Truhlar and coworkers[Yu et al.(2016a)Yu, He, Li, and Truhlar]
MPW1B95 – 31% HF exchange + 69% mPW91 GGA exchange + B95 metaGGA correlation[Zhao and Truhlar(2004)]
MPWB1K – 44% HF exchange + 56% mPW91 GGA exchange + B95 metaGGA correlation[Zhao and Truhlar(2004)]
PW6B95 – 6parameter combination of 28 % HF exchange, 72 % optimized PW91 GGA exchange, and reoptimized B95 metaGGA correlation by Zhao and Truhlar[Zhao and Truhlar(2005)]
PWB6K – 6parameter combination of 46 % HF exchange, 54 % optimized PW91 GGA exchange, and reoptimized B95 metaGGA correlation by Zhao and Truhlar[Zhao and Truhlar(2005)]
SCAN0 – 25% HF exchange + 75% SCAN metaGGA exchange + SCAN metaGGA correlation[Hui and Chai(2016)]
tHCTHh (HCTHh) – 17parameter functional with 15% HF exchange by Boese and Handy[Boese and Handy(2002)]
TPSS0 – 25% HF exchange + 75% TPSS metaGGA exchange + TPSS metaGGA correlation[Grimme(2005)]
RangeSeparated Hybrid Generalized Gradient Approximation (RSH GGA)
wB97XV (B97XV) – 10parameter combinatoriallyoptimized, dispersioncorrected (VV10) functional with 16.7% SR HF exchange, 100% LR HF exchange, and [Mardirossian and HeadGordon(2014)]
wB97XD3 (B97XD3) – 16parameter dispersioncorrected (DFTD3(0)) functional with 19.57% SR HF exchange, 100% LR HF exchange, and [Lin et al.(2013)Lin, Li, Mao, and Chai]
wB97XD (B97XD) – 15parameter dispersioncorrected (DFTCHG) functional with 22.2% SR HF exchange, 100% LR HF exchange, and [Chai and HeadGordon(2008b)]
CAMB3LYP – Coulombattenuating method functional by Handy and coworkers[Yanai et al.(2004)Yanai, Tew, and Handy]
CAMQTP00 – Reparameterized CAMB3LYP designed to satisfy the IPtheorem for all occupied orbitals of the water molecule[Verma and Bartlett(2014)]
CAMQTP01 – Reparameterized CAMB3LYP optimized to satisfy the valence IPs of the water molecule, 34 excitation states, and G21 atomization energies[Jin and Bartlett(2016)]
HSEHJS – Screenedexchange “HSE06” functional with 25% SR HF exchange, 0% LR HF exchange, and =0.11, using the updated HJS PBE exchange hole model[Krukau et al.(2006)Krukau, Vydrov, Izmaylov, and Scuseria, Henderson et al.(2008)Henderson, Janesko, and Scuseria]
LCrVV10* – LCVV10 density functional with the VV10 NLC functional replaced by the rVV10 NLC functional[Mardirossian et al.(2017)Mardirossian, Pestana, Womack, Skylaris, HeadGordon, and HeadGordon]
LCVV10 – 0% SR HF exchange + 100% LR HF exchange + PBE GGA exchange + PBE GGA correlation + VV10 nonlocal correlation (=0.45)[Vydrov and Van Voorhis(2010b)]
LCwPBE08 (LCPBE08) – 0% SR HF exchange + 100% LR HF exchange + PBE GGA exchange + PBE GGA correlation (=0.45)[Weintraub et al.(2009)Weintraub, Henderson, and Scuseria]
LRCBOP (LRCBOP)– 0% SR HF exchange + 100% LR HF exchange + muB88 GGA exchange + BOP GGA correlation (=0.47)[Song et al.(2007)Song, Hirosawa, Tsuneda, and Hirao]
LRCwPBE (LRCPBE) – 0% SR HF exchange + 100% LR HF exchange + PBE GGA exchange + PBE GGA correlation (=0.3)[Rohrdanz and Herbert(2008)]
LRCwPBEh (LRCPBEh) – 20% SR HF exchange + 100% LR HF exchange + 80% PBE GGA exchange + PBE GGA correlation (=0.2)[Rohrdanz et al.(2009)Rohrdanz, Martins, and Herbert]
N12SX – 26parameter nonseparable GGA with 25% SR HF exchange, 0% LR HF exchange, and [Peverati and Truhlar(2012d)]
rCAMB3LYP – Refit CAMB3LYP with the goal of minimizing manyelectron selfinteraction error[Cohen et al.(2007b)Cohen, MoriSánchez, and Yang]
wB97 (B97) – 13parameter functional with 0% SR HF exchange, 100% LR HF exchange, and [Chai and HeadGordon(2008a)]
wB97X (B97X) – 14parameter functional with 15.77% SR HF exchange, 100% LR HF exchange, and [Chai and HeadGordon(2008a)]
wB97XrV* (B97XrV) – B97XV density functional with the VV10 NLC functional replaced by the rVV10 NLC functional[Mardirossian et al.(2017)Mardirossian, Pestana, Womack, Skylaris, HeadGordon, and HeadGordon]
RangeSeparated Hybrid MetaGeneralized Gradient Approximation (RSH metaGGA)
wB97MV (B97MV) – 12parameter combinatoriallyoptimized, dispersioncorrected (VV10) functional with 15% SR HF exchange, 100% LR HF exchange, and [Mardirossian and HeadGordon(2016)]
M11 – 40parameter functional with 42.8% SR HF exchange, 100% LR HF exchange, and [Peverati and Truhlar(2011b)]
MN12SX – 58parameter nonseparable metaGGA with 25% SR HF exchange, 0% LR HF exchange, and [Peverati and Truhlar(2012d)]
wB97MrV* (B97XrV) – B97MV density functional with the VV10 NLC functional replaced by the rVV10 NLC functional[Mardirossian et al.(2017)Mardirossian, Pestana, Womack, Skylaris, HeadGordon, and HeadGordon]
wM05D (M05D) – 21parameter dispersioncorrected (DFTCHG) functional with 36.96% SR HF exchange, 100% LR HF exchange, and [Lin et al.(2012)Lin, Tsai, Li, and Chai]
wM06D3 (M06D3) – 25parameter dispersioncorrected [DFTD3(0)] functional with 27.15% SR HF exchange, 100% LR HF exchange, and [Lin et al.(2013)Lin, Li, Mao, and Chai]
Double Hybrid Generalized Gradient Approximation (DH GGA)
Note: In order to use the resolutionoftheidentity approximation for the MP2 component, specify an auxiliary basis set with the $rem variable AUX_BASIS
DSDPBEPBED3 – 68% HF exchange + 32% PBE GGA exchange + 49% PBE GGA correlation + 13% SS MP2 correlation + 55% OS MP2 correlation with DFTD3(BJ) tail[Kozuch and Martin(2013)]
wB97X2(LP) (B97X2(LP)) – 13parameter functional with 67.88% SR HF exchange, 100% LR HF exchange, 58.16% SS MP2 correlation, 47.80% OS MP2 correlation, and [Chai and HeadGordon(2009)]
wB97X2(TQZ) (B97X2(TQZ)) – 13parameter functional with 63.62% SR HF exchange, 100% LR HF exchange, 52.93% SS MP2 correlation, 44.71% OS MP2 correlation, and [Chai and HeadGordon(2009)]
XYG3 – 80.33% HF exchange  1.4% Slater LSDA exchange + 21.07% B88 GGA exchange + 67.89% LYP GGA correlation + 32.11% MP2 correlation (evaluated with B3LYP orbitals)[Zhang et al.(2009)Zhang, Xu, and Goddard III]
XYGJOS – 77.31% HF exchange + 22.69% Slater LSDA exchange + 23.09% VWN1RPA LSDA correlation + 27.54% LYP GGA correlation + 43.64% OS MP2 correlation (evaluated with B3LYP orbitals)[Zhang et al.(2011)Zhang, Xin, Jung, and Goddard III]
B2PLYP – 53% HF exchange + 47% B88 GGA exchange + 73% LYP GGA correlation + 27% MP2 correlation[Grimme(2006a)]
B2GPPLYP – 65% HF exchange + 35% B88 GGA exchange + 64% LYP GGA correlation + 36% MP2 correlation[Karton et al.(2008)Karton, Tarnopolsky, Lamère, Schatz, and Martin]
DSDPBEP86D3 – 69% HF exchange + 31% PBE GGA exchange + 44% P86 GGA correlation + 22% SS MP2 correlation + 52% OS MP2 correlation with DFTD3(BJ) tail[Kozuch and Martin(2013)]
LS1DHPBE – 75% HF exchange + 25% PBE GGA exchange + 57.8125% PBE GGA correlation + 42.1875% MP2 correlation[Toulouse et al.(2011)Toulouse, Sharkas., Brémond, and Adamo]
PBEQIDH – 69.3361% HF exchange + 30.6639% PBE GGA exchange + 66.6667% PBE GGA correlation + 33.3333% MP2 correlation[Brémond et al.(2014)Brémond, SanchoGarca, PérezJiménez, and Adamo]
PBE02 – 79.37% HF exchange + 20.63% PBE GGA exchange + 50% PBE GGA correlation + 50% MP2 correlation[Chai and Mao(2012)]
PBE0DH – 50% HF exchange + 50% PBE GGA exchange + 87.5% PBE GGA correlation + 12.5% MP2 correlation[Brémond and Adamo(2011)]
Double Hybrid MetaGeneralized Gradient Approximation (DH MGGA)
PTPSSD3 – 50% HF exchange + 50% ReFit TPSS metaGGA exchange + 62.5% ReFit TPSS metaGGA correlation + 37.5% OS MP2 correlation with DFTD3(0) tail[Goerigk and Grimme(2011)]
DSDPBEB95D3 – 66% HF exchange + 34% PBE GGA exchange + 55% B95 GGA correlation + 9% SS MP2 correlation + 46% OS MP2 correlation with DFTD3(BJ) tail[Kozuch and Martin(2013)]
PWPB95D3 – 50% HF exchange + 50% ReFit PW91 GGA exchange + 73.1% ReFit B95 metaGGA correlation + 26.9% OS MP2 correlation with DFTD3(0) tail[Goerigk and Grimme(2011)]
SRC1R1 – TDDFT shortrange corrected functional (Equation 1 in Ref. Besley:2009a, 1st row atoms)
SRC1R2 – TDDFT shortrange corrected functional (Equation 1 in Ref. Besley:2009a, 2nd row atoms)
SRC2R1 – TDDFT shortrange corrected functional (Equation 2 in Ref. Besley:2009a, 1st row atoms)
SRC2R2 – TDDFT shortrange corrected functional (Equation 2 in Ref. Besley:2009a, 2nd row atoms)
BR89 – BeckeRoussel metaGGA exchange functional modeled after the hydrogen atom[Becke and Roussel(1989)]
B94 – metaGGA correlation functional by Becke that uses the BR89 exchange functional to compute the Coulomb potential[Becke(1994)]
B94hyb – modified version of the B94 correlation functional for use with the BR89B94hyb exchangecorrelation functional[Becke(1994)]
BR89B94h – 15.4% HF exchange + 84.6% BR89 metaGGA exchange + BR89hyb metaGGA correlation[Becke(1994)]
BRSC – Exchange component of the original B05 exchangecorrelation functional[Becke and Johnson(2005)]
MB05 – Exchange component of the modified B05 (BM05) exchangecorrelation functional[Proynov et al.(2012a)Proynov, Liu, and Kong]
B05 – A full exactexchange KohnSham scheme of Becke that uses the exactexchange energy density (RI) and accounts for static correlation[Becke and Johnson(2005), Proynov et al.(2010)Proynov, Shao, and Kong, Proynov et al.(2012b)Proynov, Liu, Shao, and Kong]
BM05 (XC) – Modified B05 hyperGGA scheme that uses MB05 instead of BRSC as the exchange functional[Proynov et al.(2012a)Proynov, Liu, and Kong]
PSTS – HyperGGA (100% HF exchange) exchangecorrelation functional of Perdew, Staroverov, Tao, and Scuseria[Perdew et al.(2008b)Perdew, Staroverov, Tao, and Scuseria]
MCY2 – MoriSánchezCohenYang adiabatic connectionbased hyperGGA exchangecorrelation functional[MoriSánchez et al.(2006)MoriSánchez, Cohen, and Yang, Cohen et al.(2007a)Cohen, MoriSánchez, and Yang, Liu et al.(2012)Liu, Proynov, Yu, Furlani, and Kong]
Users can also request a customized density functional consisting of any linear combination of exchange and/or correlation functionals available in QChem. A “general” density functional of this sort is requested by setting EXCHANGE = GEN and then specifying the functional by means of an $xc_functional input section consisting of one line for each desired exchange (X) or correlation (C) component of the functional, and having the format shown below.
$xc_functional X exchange_symbol coefficient X exchange_symbol coefficient ... C correlation_symbol coefficient C correlation_symbol coefficient ... K coefficient $end
Each line requires three variables: X or C to designate whether this is an exchange or correlation component; the symbolic representation of the functional, as would be used for the EXCHANGE or CORRELATION keywords variables as described above; and a real number coefficient for each component. Note that HartreeFock exchange can be designated either as “X" or as “K". Examples are shown below.
Example 5.44 QChem input for HO with the B3tLap functional.
$molecule 0 1 O H1 O oh H2 O oh H1 hoh oh = 0.97 hoh = 120.0 $end $rem EXCHANGE gen CORRELATION none BASIS g3large ! recommended for high accuracy THRESH 14 ! and better convergence $end $xc_functional X Becke 0.726 X S 0.0966 C PK06 1.0 K 0.1713 $end
Example 5.45 QChem input for HO with the BR89B94hyb functional.
$molecule 0 1 O H1 O oh H2 O oh H1 hoh oh = 0.97 hoh = 120.0 $end $rem EXCHANGE gen CORRELATION none BASIS g3large ! recommended for high accuracy THRESH 14 ! and better convergence $end $xc_functional X BR89 0.846 C B94hyb 1.0 K 0.154 $end
The next two examples illustrate the use of the RIB05 and RIPSTS functionals. These are presently available only for singlepoint calculations, and convergence is greatly facilitated by obtaining converged SCF orbitals from, e.g., an LDA or HF calculation first. (LDA is used in the example below but HF can be substituted.) Use of the RI approximation (Section 6.6) requires specification of an auxiliary basis set.
Example 5.46 QChem input of H using RIB05.
$comment H2, example of SP RIB05. First do a wellconverged LSD, G3LARGE is the basis of choice for good accuracy. The input lines PURECART 2222 SCF_GUESS CORE are obligatory for the time being here. $end $molecule 0 1 H 0. 0. 0.0 H 0. 0. 0.7414 $end $rem SCF_GUESS core METHOD lda BASIS g3large PURECART 2222 THRESH 14 INCDFT false SYM_IGNORE true SYMMETRY false SCF_CONVERGENCE 9 $end @@@ $comment For the time being the following input lines are obligatory: PURECART 2222 AUX_BASIS riB05ccpvtz DFT_CUTOFFS 0 MAX_SCF_CYCLES 0 $end $molecule read $end $rem SCF_GUESS read EXCHANGE b05 ! or set to psts for ripsts PURECART 2222 BASIS g3large AUX_BASIS rib05ccpvtz ! the aux basis for both RIB05 and RIPSTS THRESH 4 PRINT_INPUT true INCDFT false SYM_IGNORE true SYMMETRY false MAX_SCF_CYCLES 0 DFT_CUTOFFS 0 $end