energy

psi4.driver.energy(name, **kwargs)[source]

Function to compute the single-point electronic energy.

Returns:float – Total electronic energy in Hartrees. SAPT & EFP return interaction energy.
Returns:(float, Wavefunction) – energy and wavefunction when return_wfn specified.
PSI variables:
Parameters:
  • name (string) –

    'scf' || 'mp2' || 'ci5' || etc.

    First argument, usually unlabeled. Indicates the computational method to be applied to the system.

  • molecule (molecule) –

    h2o || etc.

    The target molecule, if not the last molecule defined.

  • return_wfn (boolean) –

    'on' || \(\Rightarrow\) 'off' \(\Leftarrow\)

    Indicate to additionally return the Wavefunction calculation result as the second element (after float energy) of a tuple.

  • restart_file (string) –

    ['file.1, file.32] || ./file || etc.

    Binary data files to be renamed for calculation restart.

name calls method
efp effective fragment potential (EFP) [manual]
scf Hartree–Fock (HF) or density functional theory (DFT) [manual]
hf HF self consistent field (SCF) [manual]
hf3c HF with dispersion, BSSE, and basis set corrections [manual]
pbeh3c PBEh with dispersion, BSSE, and basis set corrections [manual]
dcft density cumulant functional theory [manual]
mp2 2nd-order Møller–Plesset perturbation theory (MP2) [manual] [details]
mp3 3rd-order Møller–Plesset perturbation theory (MP3) [manual] [details]
fno-mp3 MP3 with frozen natural orbitals [manual]
mp2.5 average of MP2 and MP3 [manual] [details]
mp4(sdq) 4th-order MP perturbation theory (MP4) less triples [manual]
fno-mp4(sdq) MP4 (less triples) with frozen natural orbitals [manual]
mp4 full MP4 [manual] [details]
fno-mp4 full MP4 with frozen natural orbitals [manual]
mpn nth-order Møller–Plesset (MP) perturbation theory [manual]
zaptn nth-order z-averaged perturbation theory (ZAPT) [manual]
omp2 orbital-optimized second-order MP perturbation theory [manual]
scs-omp2 spin-component scaled OMP2 [manual]
scs(n)-omp2 a special version of SCS-OMP2 for nucleobase interactions [manual]
scs-omp2-vdw a special version of SCS-OMP2 (from ethene dimers) [manual]
sos-omp2 spin-opposite scaled OMP2 [manual]
sos-pi-omp2 A special version of SOS-OMP2 for pi systems [manual]
omp3 orbital-optimized third-order MP perturbation theory [manual]
scs-omp3 spin-component scaled OMP3 [manual]
scs(n)-omp3 a special version of SCS-OMP3 for nucleobase interactions [manual]
scs-omp3-vdw a special version of SCS-OMP3 (from ethene dimers) [manual]
sos-omp3 spin-opposite scaled OMP3 [manual]
sos-pi-omp3 A special version of SOS-OMP3 for pi systems [manual]
omp2.5 orbital-optimized MP2.5 [manual]
lccsd, cepa(0) coupled electron pair approximation variant 0 [manual] [details]
fno-lccsd, fno-cepa(0) CEPA(0) with frozen natural orbitals [manual]
cepa(1) coupled electron pair approximation variant 1 [manual]
fno-cepa(1) CEPA(1) with frozen natural orbitals [manual]
cepa(3) coupled electron pair approximation variant 3 [manual]
fno-cepa(3) CEPA(3) with frozen natural orbitals [manual]
acpf averaged coupled-pair functional [manual]
fno-acpf ACPF with frozen natural orbitals [manual]
aqcc averaged quadratic coupled cluster [manual]
fno-aqcc AQCC with frozen natural orbitals [manual]
qcisd quadratic CI singles doubles (QCISD) [manual]
fno-qcisd QCISD with frozen natural orbitals [manual]
lccd Linear CCD [manual] [details]
fno-lccd LCCD with frozen natural orbitals [manual]
olccd orbital optimized LCCD [manual]
cc2 approximate coupled cluster singles and doubles (CC2) [manual]
ccd coupled cluster doubles (CCD) [manual]
ccsd coupled cluster singles and doubles (CCSD) [manual] [details]
bccd Brueckner coupled cluster doubles (BCCD) [manual]
fno-ccsd CCSD with frozen natural orbitals [manual]
qcisd(t) QCISD with perturbative triples [manual]
fno-qcisd(t) QCISD(T) with frozen natural orbitals [manual]
ccsd(t) CCSD with perturbative triples (CCSD(T)) [manual] [details]
ccsd(at) CCSD with asymmetric perturbative triples (CCSD(AT)) [manual] [details]
bccd(t) BCCD with perturbative triples [manual]
fno-ccsd(t) CCSD(T) with frozen natural orbitals [manual]
cc3 approximate CC singles, doubles, and triples (CC3) [manual]
ccenergy expert full control over ccenergy module
dfocc expert full control over dfocc module
cisd configuration interaction (CI) singles and doubles (CISD) [manual] [details]
fno-cisd CISD with frozen natural orbitals [manual]
cisdt CI singles, doubles, and triples (CISDT) [manual]
cisdtq CI singles, doubles, triples, and quadruples (CISDTQ) [manual]
cin nth-order CI [manual]
fci full configuration interaction (FCI) [manual]
detci expert full control over detci module
casscf complete active space self consistent field (CASSCF) [manual]
rasscf restricted active space self consistent field (RASSCF) [manual]
mcscf multiconfigurational self consistent field (SCF) [manual]
psimrcc Mukherjee multireference coupled cluster (Mk-MRCC) [manual]
dmrg-scf density matrix renormalization group SCF [manual]
dmrg-caspt2 density matrix renormalization group CASPT2 [manual]
dmrg-ci density matrix renormalization group CI [manual]
sapt0 0th-order symmetry adapted perturbation theory (SAPT) [manual]
ssapt0 0th-order SAPT with special exchange scaling [manual]
fisapt0 0th-order functional and/or intramolecular SAPT [manual]
sapt2 2nd-order SAPT, traditional definition [manual]
sapt2+ SAPT including all 2nd-order terms [manual]
sapt2+(3) SAPT including perturbative triples [manual]
sapt2+3 SAPT including all 3rd-order terms [manual]
sapt2+(ccd) SAPT2+ with CC-based dispersion [manual]
sapt2+(3)(ccd) SAPT2+(3) with CC-based dispersion [manual]
sapt2+3(ccd) SAPT2+3 with CC-based dispersion [manual]
sapt2+dmp2 SAPT including all 2nd-order terms and MP2 correction [manual]
sapt2+(3)dmp2 SAPT including perturbative triples and MP2 correction [manual]
sapt2+3dmp2 SAPT including all 3rd-order terms and MP2 correction [manual]
sapt2+(ccd)dmp2 SAPT2+ with CC-based dispersion and MP2 correction [manual]
sapt2+(3)(ccd)dmp2 SAPT2+(3) with CC-based dispersion and MP2 correction [manual]
sapt2+3(ccd)dmp2 SAPT2+3 with CC-based dispersion and MP2 correction [manual]
sapt0-ct 0th-order SAPT plus charge transfer (CT) calculation [manual]
sapt2-ct SAPT2 plus CT [manual]
sapt2+-ct SAPT2+ plus CT [manual]
sapt2+(3)-ct SAPT2+(3) plus CT [manual]
sapt2+3-ct SAPT2+3 plus CT [manual]
sapt2+(ccd)-ct SAPT2+(CCD) plus CT [manual]
sapt2+(3)(ccd)-ct SAPT2+(3)(CCD) plus CT [manual]
sapt2+3(ccd)-ct SAPT2+3(CCD) plus CT [manual]
adc 2nd-order algebraic diagrammatic construction (ADC) [manual]
eom-cc2 EOM-CC2 [manual]
eom-ccsd equation of motion (EOM) CCSD [manual]
eom-cc3 EOM-CC3 [manual]
name calls method DFT [manual]
b1lyp B1LYP Hyb-GGA Exchange-Correlation Functional
b1lyp-d3bj  
b1pw91 B1PW91 Hyb-GGA Exchange-Correlation Functional
b1wc B1WC Hyb-GGA Exchange-Correlation Functional
b2gpplyp B2GPPLYP Double Hybrid Exchange-Correlation Functional
b2gpplyp-d3bj  
b2gpplyp-nl B2GPPLYP Double Hybrid Exchange-Correlation Functional
b2plyp B2PLYP Double Hybrid Exchange-Correlation Functional
b2plyp-d3bj  
b2plyp-d3mbj  
b2plyp-nl B2PLYP Double Hybrid Exchange-Correlation Functional
b3lyp B3LYP Hyb-GGA Exchange-Correlation Functional
b3lyp-d3bj  
b3lyp-d3mbj  
b3lyp-nl B3LYP-nl Hyb-GGA Exchange-Correlation Functional
b3lyp5 B3LYP5 Hyb-GGA Exchange-Correlation Functional
b3lyps B3LYPs Hyb-GGA Exchange-Correlation Functional
b3p86 B3P86 Hyb-GGA Exchange-Correlation Functional
b3p86-d3bj  
b3pw91 B3PW91 Hyb-GGA Exchange-Correlation Functional
b3pw91-d3bj  
b3pw91-nl B3PW91-nl Hyb-GGA Exchange-Correlation Functional
b5050lyp B5050LYP Hyb-GGA Exchange-Correlation Functional
b86b95 B86B95 Hyb-GGA Exchange-Correlation Functional
b86bpbe B86BPBE GGA Exchange-Correlation Functional
b88b95 B88B95 Hyb-GGA Exchange-Correlation Functional
b88b95-d3bj  
b97-0 B97-0 Hyb-GGA Exchange-Correlation Functional
b97-1 B97-1 Hyb-GGA Exchange-Correlation Functional
b97-1-d3bj  
b97-1p B97-1p Hyb-GGA Exchange-Correlation Functional
b97-2 B97-2 Hyb-GGA Exchange-Correlation Functional
b97-2-d3bj  
b97-3 B97-3 Hyb-GGA Exchange-Correlation Functional
b97-d  
b97-d3bj  
b97-d3mbj  
b97-gga1 B97-GGA1 GGA Exchange-Correlation Functional
b97-k B97-K Hyb-GGA Exchange-Correlation Functional
b97m-d3bj  
b97m-v B97M-V GGA Exchange-Correlation Functional
bb1k BB1K Hyb-GGA Exchange-Correlation Functional
bhandh BHandH Hyb-GGA Exchange-Correlation Functional
bhandhlyp BHandHLYP Hyb-GGA Exchange-Correlation Functional
blyp BLYP GGA Exchange-Correlation Functional
blyp-d3bj  
blyp-d3mbj  
blyp-nl BLYP GGA Exchange-Correlation Functional
bop BOP GGA Exchange-Correlation Functional
bop-d3bj  
bp86 BP86 GGA Exchange-Correlation Functional
bp86-d3bj  
bp86-d3mbj  
bp86-nl BP86 GGA Exchange-Correlation Functional
cam-b3lyp CAM-B3LYP Hyb-GGA Exchange-Correlation Functional
cam-b3lyp-d3bj  
cap0 CAP0 Hyb-GGA Exchange-Correlation Functional
core-dsd-blyp  
core-dsd-blyp-d3bj  
dldf Dispersionless Hybrid Meta-GGA XC Functional
dldf+d09 Dispersionless Hybrid Meta-GGA XC Functional
dldf+d10 Dispersionless Hybrid Meta-GGA XC Functional
dsd-blyp DSD-BLYP SCS Double Hybrid XC Functional (not dispersion corrected)
dsd-blyp-d3bj  
dsd-blyp-nl DSD-BLYP-NL (D3BJ,FC parameters) VV10 SCS Double Hybrid XC Functional
dsd-pbeb95 DSD-PBEB95 SCS Double Hybrid Meta-GGA XC Functional (not dispersion corrected)
dsd-pbeb95-d3bj  
dsd-pbeb95-nl DSD-PBEB95-NL (D3BJ parameters) VV10 SCS Double Hybrid Meta-GGA XC Functional
dsd-pbep86 DSD-PBEP86 SCS Double Hybrid XC Functional (not dispersion corrected)
dsd-pbep86-d3bj  
dsd-pbep86-nl DSD-PBEP86-NL (D3BJ parameters) VV10 SCS Double Hybrid XC Functional
dsd-pbepbe DSD-PBEPBE SCS Double Hybrid XC Functional (not dispersion corrected)
dsd-pbepbe-d3bj  
dsd-pbepbe-nl DSD-PBEPBE-NL (D3BJ parameters) VV10 SCS Double Hybrid XC Functional
edf1 EDF1 GGA Exchange-Correlation Functional
edf2 EDF2 Hyb-GGA Exchange-Correlation Functional
ft97 FT97 GGA Exchange-Correlation Functional
gam GAM GGA Minessota Exchange-Correlation Functional
hcth120 HCTH120 GGA Exchange-Correlation Functional
hcth120-d3bj  
hcth147 HCTH147 GGA Exchange-Correlation Functional
hcth407 HCTH407 GGA Exchange-Correlation Functional
hcth407-d3bj  
hcth407p HCTH407P GGA Exchange-Correlation Functional
hcth93 HCTH93 GGA Exchange-Correlation Functional
hcthp14 HCTHP14 GGA Exchange-Correlation Functional
hcthp76 HCTHP76 GGA Exchange-Correlation Functional
hf  
hf+d  
hf-d3bj  
hf-nl  
hf3c Hartree Fock based 3C composite method with minimal basis set, gCP and D3(BJ)
hjs-b88 HJS-B88 Hyb-GGA Exchange-Correlation Functional
hjs-b97x HJS-B97X Hyb-GGA Exchange-Correlation Functional
hjs-pbe HJS-PBE Hyb-GGA Exchange-Correlation Functional
hjs-pbe-sol HJS-PBE-SOL Hyb-GGA Exchange-Correlation Functional
hpbeint HPBEINT Hyb-GGA Exchange-Correlation Functional
hse03 HSE03 Hyb-GGA Exchange-Correlation Functional
hse03-d3bj  
hse06 HSE06 Hyb-GGA Exchange-Correlation Functional
hse06-d3bj  
ksdt KSDT Exchange-Correlation Functional
kt2 KT2 GGA Exchange-Correlation Functional
lc-vv10 LC-VV10 GGA Exchange-Correlation Functional
lrc-wpbe LRC-WPBE GGA Exchange-Correlation Functional
lrc-wpbeh LRC-wPBEh Hyb-GGA Exchange-Correlation Functional
m05 M05 Meta-GGA XC Functional
m05-2x Heavily Parameterized Hybrid M05-2X Meta-GGA XC Functional
m06 M06 Meta-GGA XC Functional
m06-2x Hybrid M06-2X Meta-GGA XC Functional
m06-hf Minnesota M06-HF Hybrid XC Functional
m06-l M06-L Meta-GGA XC Functional
m08-hx Minnesota M08-HX Hybrid XC Functional
m08-so Minnesota M08-SO Hybrid XC Functional
m11 M11 Meta-GGA XC Functional
m11-d3bj  
m11-l M11-L Meta-GGA XC Functional
m11-l-d3bj  
mb3lyp-rc04 MB3LYP-RC04 Hyb-GGA Exchange-Correlation Functional
mgga_ms0 MGGA_MS0 Meta-GGA XC Functional
mgga_ms1 MGGA_MS1 Meta-GGA XC Functional
mgga_ms2 MGGA_MS2 Meta-GGA XC Functional
mgga_ms2h MGGA_MS2h Hybrid Meta-GGA XC Functional
mgga_mvs MGGA_MVS Meta-GGA XC Functional
mgga_mvsh MGGA_MV2h Hybrid Meta-GGA XC Functional
mn12-l MN12-L Meta-GGA XC Functional
mn12-l-d3bj  
mn12-sx MN12-SX Meta-GGA Hybrid Screened Exchange-Correlation Functional
mn12-sx-d3bj  
mn15 MN15 Hybrid Meta-GGA Exchange-Correlation Functional
mn15-d3bj  
mn15-l MN15-L Meta-GGA XC Functional
mohlyp MOHLYP GGA Exchange-Correlation Functional
mohlyp2 MOHLYP2 GGA Exchange-Correlation Functional
mpw1b95 mPW1B95 Hyb-GGA Exchange-Correlation Functional
mpw1b95-d3bj  
mpw1k mPW1K Hyb-GGA Exchange-Correlation Functional
mpw1lyp mPW1LYP Hybrid GGA Exchange-Correlation Functional
mpw1pbe mPW1PBE Hybrid GGA Exchange-Correlation Functional
mpw1pw mPW1PW Hyb-GGA Exchange-Correlation Functional
mpw1pw-d3bj  
mpw3lyp mPW3LYP Hyb-GGA Exchange-Correlation Functional
mpw3pw mPW3PW Hyb-GGA Exchange-Correlation Functional
mpwb1k mPWB1K Hyb-GGA Exchange-Correlation Functional
mpwb1k-d3bj  
mpwlyp1m mPWLYP1M Hyb-GGA Exchange-Correlation Functional
mpwlyp1w mPWLYP1W GGA Exchange-Correlation Functional
mpwpw mPWPW GGA Exchange-Correlation Functional
n12 N12 nonseparable GGA Exchange-Correlation Functional
n12-d3bj  
n12-sx N12-SX Hybrid nonseparable GGA Exchange-Correlation Functional
n12-sx-d3bj  
o3lyp O3LYP Hyb-GGA Exchange-Correlation Functional
o3lyp-d3bj  
oblyp-d  
op-pbe BP86 GGA Exchange-Correlation Functional
opbe-d  
opwlyp-d  
otpss-d  
pbe PBE GGA Exchange-Correlation Functional
pbe-d3bj  
pbe-d3mbj  
pbe-nl PBE GGA Exchange-Correlation Functional
pbe0 PBE0 Hyb-GGA Exchange-Correlation Functional
pbe0-13 PBE0-13 Hyb-GGA Exchange-Correlation Functional
pbe0-2 PBE0-2 Double Hybrid Exchange-Correlation Functional
pbe0-d3bj  
pbe0-d3mbj  
pbe0-dh  
pbe0-nl PBE0-nl Hyb-GGA Exchange-Correlation Functional
pbe1w PBE1W GGA Exchange-Correlation Functional
pbe50 PBE50 Hybrid GGA Exchange-Correlation Functional
pbeh3c PBE Hybrid based 3C composite method with a small basis set, gCP and D3(BJ)
pbelyp1w PBELYP1W GGA Exchange-Correlation Functional
pkzb PKZB Meta-GGA XC Functional
ptpss PTPSS SOS Double Hybrid XC Functional
ptpss-d3bj  
pw6b95 PW6B95 Hybrid Meta-GGA XC Functional
pw6b95-d3bj  
pw86b95 PW86B95 Hyb-GGA Exchange-Correlation Functional
pw86pbe PW86PBE GGA Exchange-Correlation Functional
pw91 PW91 GGA Exchange-Correlation Functional
pw91-d3bj  
pwb6k PWB6K Hyb-GGA Exchange-Correlation Functional
pwb6k-d3bj  
pwpb95 PWPB95 SOS Double Hybrid XC Functional
pwpb95-d3bj  
pwpb95-nl PWPB95 SOS Double Hybrid XC Functional
revb3lyp revB3LYP Hyb-GGA Exchange-Correlation Functional
revpbe revPBE GGA Exchange-Correlation Functional
revpbe-d3bj  
revpbe-nl revPBE GGA Exchange-Correlation Functional
revpbe0 revPBE0 Hybrid GGA Exchange-Correlation Functional
revpbe0-d3bj  
revpbe0-nl revPBE0 Hybrid GGA Exchange-Correlation Functional
revtpss revised TPSS Meta-GGA XC Functional
revtpss-d3bj  
revtpss-nl revised TPSS Meta-GGA XC Functional
revtpssh revTPSSh Hyb-GGA Exchange-Correlation Functional
revtpssh-d3bj  
rpbe RPBE GGA Exchange-Correlation Functional
rpbe-d3bj  
sb98-1a SB98-1a Hyb-GGA Exchange-Correlation Functional
sb98-1b SB98-1b Hyb-GGA Exchange-Correlation Functional
sb98-1c SB98-1c Hyb-GGA Exchange-Correlation Functional
sb98-2a SB98-2a Hyb-GGA Exchange-Correlation Functional
sb98-2b SB98-2b Hyb-GGA Exchange-Correlation Functional
sb98-2c SB98-2c Hyb-GGA Exchange-Correlation Functional
sogga SOGGA Exchange + PBE Correlation Functional
sogga11 SOGGA11 Exchange-Correlation Functional
sogga11-x SOGGA11-X Hybrid Exchange-Correlation Functional
sogga11-x-d3bj  
svwn SVWN3 (RPA) LSDA Functional
teter93 TETER93 Exchange-Correlation Functional
th-fc TH-FC GGA Exchange-Correlation Functional
th-fcfo TH-FCFO GGA Exchange-Correlation Functional
th-fco TH-FCO GGA Exchange-Correlation Functional
th-fl TH-FL GGA Exchange-Correlation Functional
th1 TH1 GGA Exchange-Correlation Functional
th2 TH2 GGA Exchange-Correlation Functional
th3 TH3 GGA Exchange-Correlation Functional
th4 TH4 GGA Exchange-Correlation Functional
tpss TPSS Meta-GGA XC Functional
tpss-d3bj  
tpss-nl TPSS Meta-GGA XC Functional
tpssh TPSSh Hyb-GGA Exchange-Correlation Functional
tpssh-d3bj  
tpssh-nl TPSSh-nl Hyb-GGA Exchange-Correlation Functional
tpsslyp1w TPSSLYP1W GGA Exchange-Correlation Functional
tuned-cam-b3lyp TUNED-CAM-B3LYP Hyb-GGA Exchange-Correlation Functional
vsxc VSXC Meta-GGA XC Functional
vv10 VV10 GGA Exchange-Correlation Functional
wb97 wB97 GGA Exchange-Correlation Functional
wb97m-d3bj  
wb97m-v wB97M-V Hyb-GGA Exchange-Correlation Functional
wb97x wB97X Hyb-GGA Exchange-Correlation Functional
wb97x-d  
wb97x-d3bj  
wb97x-v wB97X-V Hyb-GGA Exchange-Correlation Functional
wpbe PBE SR-XC Functional (HJS Model)
wpbe-d3bj  
wpbe-d3mbj  
wpbe0 PBE0 SR-XC Functional (HJS Model)
x1b95 X1B95 Hyb-GGA Exchange-Correlation Functional
x3lyp X3LYP Hyb-GGA Exchange-Correlation Functional
x3lyp-d3bj  
xb1k XB1K Hyb-GGA Exchange-Correlation Functional
xlyp XLYP GGA Exchange-Correlation Functional
xlyp-d3bj  
zlp ZLP GGA Exchange-Correlation Functional
name calls method in Kallay’s MRCC program [manual]
mrccsd CC through doubles
mrccsdt CC through triples
mrccsdtq CC through quadruples
mrccsdtqp CC through quintuples
mrccsdtqph CC through sextuples
mrccsd(t) CC through doubles with perturbative triples
mrccsdt(q) CC through triples with perturbative quadruples
mrccsdtq(p) CC through quadruples with pertubative quintuples
mrccsdtqp(h) CC through quintuples with pertubative sextuples
mrccsd(t)_l  
mrccsdt(q)_l  
mrccsdtq(p)_l  
mrccsdtqp(h)_l  
mrccsdt-1a CC through doubles with iterative triples (cheapest terms)
mrccsdtq-1a CC through triples with iterative quadruples (cheapest terms)
mrccsdtqp-1a CC through quadruples with iterative quintuples (cheapest terms)
mrccsdtqph-1a CC through quintuples with iterative sextuples (cheapest terms)
mrccsdt-1b CC through doubles with iterative triples (cheaper terms)
mrccsdtq-1b CC through triples with iterative quadruples (cheaper terms)
mrccsdtqp-1b CC through quadruples with iterative quintuples (cheaper terms)
mrccsdtqph-1b CC through quintuples with iterative sextuples (cheaper terms)
mrcc2 approximate CC through doubles
mrcc3 approximate CC through triples
mrcc4 approximate CC through quadruples
mrcc5 approximate CC through quintuples
mrcc6 approximate CC through sextuples
mrccsdt-3 CC through doubles with iterative triples (all but the most expensive terms)
mrccsdtq-3 CC through triples with iterative quadruples (all but the most expensive terms)
mrccsdtqp-3 CC through quadruples with iterative quintuples (all but the most expensive terms)
mrccsdtqph-3 CC through quintuples with iterative sextuples (all but the most expensive terms)
name calls method in Stanton and Gauss’s CFOUR program [manual]
c4-scf Hartree–Fock (HF)
c4-mp2 2nd-order Møller–Plesset perturbation theory (non-density-fitting) (MP2)
c4-mp3 3rd-order Møller–Plesset perturbation theory (MP3)
c4-mp4(sdq) 4th-order MP perturbation theory (MP4) less triples
c4-mp4 full MP4
c4-cc2 approximate coupled cluster singles and doubles (CC2)
c4-ccsd coupled cluster singles and doubles (CCSD)
c4-cc3 approximate CC singles, doubles, and triples (CC3)
c4-ccsd(t) CCSD with perturbative triples (CCSD(T))
c4-ccsdt coupled cluster singles, doubles, and triples (CCSDT)
cfour expert full control over cfour program
Examples:
>>> # [1] Coupled-cluster singles and doubles calculation with psi code
>>> energy('ccsd')
>>> # [2] Charge-transfer SAPT calculation with scf projection from small into
>>> #     requested basis, with specified projection fitting basis
>>> set basis_guess true
>>> set df_basis_guess jun-cc-pVDZ-JKFIT
>>> energy('sapt0-ct')
>>> # [3] Arbitrary-order MPn calculation
>>> energy('mp7')
>>> # [4] Converge scf as singlet, then run detci as triplet upon singlet reference
>>> # Note that the integral transformation is not done automatically when detci is run in a separate step.
>>> molecule H2 {\n0 1\nH\nH 1 0.74\n}
>>> set basis cc-pVDZ
>>> set reference rohf
>>> scf_e, scf_wfn = energy('scf', return_wfn=True)
>>> H2.set_multiplicity(3)
>>> core.MintsHelper(scf_wfn.basisset()).integrals()
>>> energy('detci', ref_wfn=scf_wfn)
>>> # [5] Run two CI calculations, keeping the integrals generated in the first one.
>>> molecule ne {\nNe\n}
>>> set basis cc-pVDZ
>>> cisd_e, cisd_wfn = energy('cisd', return_wfn=True)
>>> energy('fci', ref_wfn=cisd_wfn)
>>> # [6] Can automatically perform complete basis set extrapolations
>>> energy("CCSD/cc-pV[DT]Z")
>>> # [7] Can automatically perform delta corrections that include extrapolations
>>> # even with a user-defined extrapolation formula. See sample inputs named
>>> # cbs-xtpl* for more examples of this input style
>>> energy("MP2/aug-cc-pv([d,t]+d)z + d:ccsd(t)/cc-pvdz", corl_scheme=myxtplfn_2)