Single-Point Energy — energy()
¶
- psi4.energy(name[, molecule, return_wfn, restart_file])[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 (str) –
'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.write_orbitals (str, boolean) –
filename
|| \(\Rightarrow\)'on'
\(\Leftarrow\) ||'off'
(str) Save wfn containing current orbitals to the given file name after each SCF iteration and retain after PSI4 finishes.
(boolean) Turns writing the orbitals after the converged SCF on/off. Orbital file will be deleted unless PSI4 is called with -m flag.
restart_file (str) –
['file.1, file.32]
||./file
|| etc.Existing files to be renamed and copied for calculation restart, e.g. a serialized wfn or module-specific binary data.
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]
dct
density cumulant (functional) theory [manual]
mp2
2nd-order Møller–Plesset perturbation theory (MP2) [manual] [details]
dlpno-mp2
local MP2 with pair natural orbital domains [manual]
mp3
3rd-order Møller–Plesset perturbation theory (MP3) [manual] [details]
fno-mp3
MP3 with frozen natural orbitals [manual]
mp2.5
mp4(sdq)
4th-order MP perturbation theory (MP4) less triples [manual]
fno-mp4(sdq)
MP4 (less triples) with frozen natural orbitals [manual]
mp4
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
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)
a-ccsd(t)
CCSD with asymmetric perturbative triples (A-CCSD(T)) [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
bmk
BMK Hybrid Meta-GGA XC Functional for kinetics
bmk-d3bj
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
bp86-vwn
BP86 GGA XC Functional based on VWN5 corr. & more accurate ftilde value
cam-b3lyp
CAM-B3LYP Hyb-GGA Exchange-Correlation Functional
cam-b3lyp-d3bj
cam-lda0
CAM-LDA0 Exchange-Correlation Functional
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-d3mbj
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
kmlyp
KMLYP Hyb-GGA Exchange-Correlation Functional
ksdt
KSDT Exchange-Correlation Functional
kt2
KT2 GGA Exchange-Correlation Functional
lc-bop
LC-BOP GGA Exchange-Correlation Functional
lc-vv10
LC-VV10 GGA Exchange-Correlation Functional
lda0
LDA0 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
mp2d
mp2mp2
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
pbe-sol
Perdew, Burke & Ernzerhof exchange (solids)
pbe-sol-d3bj
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-dh-d3bj
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
revm06-l
Revised M06-L Meta-GGA XC 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
revscan
Revised SCAN Meta-GGA XC Functional
revscan0
Revised SCAN0 Hybrid Meta-GGA XC 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
scan
SCAN Meta-GGA XC Functional
scan-d3bj
scan0
SCAN0 Hybrid Meta-GGA XC 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
t-hcth
Tau HCTH Meta-GGA XC Functional
t-hcth-d3bj
t-hcthh
Hybrid Tau HCTH Meta-GGA XC 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-d3
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)