psi4.driver.energy

psi4.driver.energy(name, **kwargs)

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:

CURRENT ENERGY CURRENT REFERENCE ENERGY CURRENT CORRELATION ENERGY

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]
b2plyp	B2PLYP Double Hybrid Exchange-Correlation Functional
b2plyp-d
b2plyp-d3
b2plyp-d3bj
b2plyp-d3m
b2plyp-d3mbj
b3lyp	B3LYP Hybrid-GGA Exchange-Correlation Functional (VWN1-RPA)
b3lyp-d
b3lyp-d3
b3lyp-d3bj
b3lyp-d3m
b3lyp-d3mbj
b3lyp5	B3LYP5 Hybrid-GGA Exchange-Correlation Functional (VWN5)
b3_x	Becke88 GGA Exchange (B3LYP weighting)
b86bpbe	B86BPBE GGA Exchange-Correlation Functional
b88_x	Becke88 GGA Exchange
b97-0	B97-0 Hybrid-GGA Exchange-Correlation Functional
b97-1	B97-1 Hybrid-GGA Exchange-Correlation Functional
b97-2	B97-2 Hybrid-GGA Exchange-Correlation Functional
b97-d
b97-d3
b97-d3bj
b97-d3m
b97-d3mbj
blyp	BLYP GGA Exchange-Correlation Functional
blyp-d
blyp-d3
blyp-d3bj
blyp-d3m
blyp-d3mbj
bp86	BP86 GGA Exchange-Correlation Functional
bp86-d
bp86-d3
bp86-d3bj
bp86-d3m
bp86-d3mbj
ft97	FT97 GGA Exchange-Correlation Functional
ft97b_x	Filitov and Theil 1997 Exchange
ft97_c	FT97 Correlation (Involves Ei functions)
hcth	HCTH Pure-GGA Exchange-Correlation Functional
hcth120	HCTH120 Pure-GGA Exchange-Correlation Functional
hcth120-d3
hcth120-d3bj
hcth147	HCTH147 Pure-GGA Exchange-Correlation Functional
hcth407	HCTH407 Pure-GGA Exchange-Correlation Functional
hf	Hartree Fock as Roothan prescribed
hf+d
hf-d3
hf-d3bj
hf3c	Hartree Fock as Roothan prescribed plus 3C
hf_x	Hartree-Fock Exchange Functional
lyp_c	LYP Correlation
m05	Heavily Parameterized Hybrid Meta-GGA XC Functional
m05-2x	Heavily Parameterized Hybrid Meta-GGA XC Functional
m05-2x-d3
m05-d3
p86_c	P86 Correlation (PZ81 LSDA + P86 GGA)
pbe	PBE GGA Exchange-Correlation Functional
pbe-d
pbe-d3
pbe-d3bj
pbe-d3m
pbe-d3mbj
pbe0	PBE0 Hybrid GGA Exchange-Correlation Functional
pbe0-2	PBE0-2 Double Hydrid Exchange-Correlation Functional
pbe0-d
pbe0-d3
pbe0-d3bj
pbe0-d3m
pbe0-d3mbj
pbea_c	New Implementation of PBEC in wPBEc-sr.
pbeh3c	PBE-3C Hybrid GGA Exchange-Correlation Functional
pbesol_x	PBEsol GGA Exchange Hole (Parameter Free)
pbe_c	PBE Correlation
pbe_x	PBE GGA Exchange Hole (Parameter Free)
pw86pbe	PW86PBE GGA Exchange-Correlation Functional
pw91	PW91 GGA Exchange-Correlation Functional
pw91_c	PW91 Correlation
pw91_x	PW91 Parameterized GGA Exchange
pw92a_c	New Implementation of PW92C in wPBEc-sr.
pw92_c
pz81_c	PZ81 Correlation
rpbe_x	RPBE GGA Exchange Hole (Parameter Free)
sogga	Second Order GGA Exchange-Correlation Functional
sogga_x	Second Order GGA Exchange Hole (Parameter Free)
svwn	SVWN3 (RPA) LSDA Functional
s_x	Slater LSDA Exchange
vwn3rpa_c	VWN3 LSDA Correlation, RPA Parameters, VWN1 Spin Polarization
vwn3_c	VWN3 LSDA Correlation, QMC Parameters, VWN1 Spin Polarization
vwn5rpa_c	VWN5 LSDA Correlation, RPA Parameters, VWN5 Spin Polarization
vwn5_c	VWN5 LSDA Correlation, QMC Parameters, VWN5 Spin Polarization
dldf	Dispersionless Hybrid Meta-GGA XC Functional
dldf+d	Dispersionless Hybrid Meta-GGA XC Functional
dldf+d09	Dispersionless Hybrid Meta-GGA XC Functional
wb88_x	B88 Short-Range GGA Exchange (HJS Model)
wb97	Parameterized LRC B97 GGA XC Functional
wb97x	Parameterized Hybrid LRC B97 GGA XC Functional
wb97x-d
wblyp	BLYP SR-XC Functional (HJS Model)
wpbe	PBE SR-XC Functional (HJS Model)
wpbe-d3
wpbe-d3bj
wpbe-d3m
wpbe-d3mbj
wpbe0	PBE0 SR-XC Functional (HJS Model)
wpbe2	Double-Hybrid PBE LRC Functional
wpbe_c	Short-Range PBE Correlation Functional
wpbe_x	PBE Short-Range GGA Exchange (HJS Model)
wpbesol	PBEsol SR-XC Functional (HJS Model)
wpbesol0	PBEsol0 SR-XC Functional (HJS Model)
wpbesol_x	PBEsol Short-Range GGA Exchange (HJS Model)
wpw92_c	Short-Range PW92 Correlation Functional
wsvwn	LSDA SR-XC Functional
ws_x	Slater Short-Range LSDA Exchange

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)