Energy¶
- energy(name[, bypass_scf, molecule])[source]¶
Function to compute the single-point electronic energy.
Returns: (float) Total electronic energy in Hartrees. SAPT returns interaction energy. Psi variables: name calls method scf Hartree–Fock (HF) or density functional theory (DFT) mp2 2nd-order Moller-Plesset perturbation theory (MP2) df-mp2 MP2 with density fitting dcft density cumulant functional theory mcscf multiconfigurational self consistent field (SCF) sapt0 0th-order symmetry adapted perturbation theory (SAPT) sapt2 2nd-order SAPT, traditional definition sapt2+ SAPT including all 2nd-order terms sapt2+(3) SAPT including perturbative triples sapt2+3 sapt0-ct 0th-order SAPT plus charge transfer (CT) calculation sapt2-ct SAPT2 plus CT sapt2+-ct SAPT2+ plus CT sapt2+(3)-ct SAPT2+(3) plus CT sapt2+3-ct SAPT2+3 plus CT cc2 approximate coupled cluster singles and doubles (CC2) ccsd coupled cluster singles and doubles (CCSD) bccd Brueckner coupled cluster doubles (BCCD) cc3 approximate coupled cluster singles, doubles, and triples (CC3) ccsd(t) CCSD with perturbative triples bccd(t) BCCD with perturbative triples ccenergy expert full control over ccenergy module mpn nth-order Moller–Plesset perturbation theory zaptn nth-order z-averaged perturbation theory (ZAPT) cisd configuration interaction (CI) singles and doubles (CISD) cisdt CI singles, doubles, and triples (CISDT) cisdtq CI singles, doubles, triples, and quadruples (CISDTQ) cin nth-order CI fci full configuration interaction (FCI) detci expert full control over detci module adc 2nd-order algebraic diagrammatic construction (ADC) eom-cc2 EOM-CC2 eom-ccsd equation of motion (EOM) CCSD eom-cc3 EOM-CC3 name calls method (aliases to name = ‘scf’) hf HF rhf HF with restricted reference uhf HF with unrestricted reference rohf HF with restricted open-shell reference rscf HF or DFT with restricted reference uscf HF or DFT with unrestricted reference roscf HF or DFT with restricted open-shell reference df-scf HF or DFT with density fitting name calls method b3lyp B3LYP Hybrid-GGA Exchange-Correlation Functional b3lyp-d B3LYP Hybrid-GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction b3lyp5 B3LYP5 Hybrid-GGA Exchange-Correlation Functional b3lyp5-d B3LYP5 Hybrid-GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction b3_x Becke88 GGA Exchange (B3LYP weighting) 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-D Pure-GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction blyp BLYP GGA Exchange-Correlation Functional blyp-d BLYP GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction bp86 BP86 GGA Exchange-Correlation Functional 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 hcth147 HCTH147 Pure-GGA Exchange-Correlation Functional hcth407 HCTH407 Pure-GGA Exchange-Correlation Functional lyp_c LYP Correlation m05 Heavily Parameterized Hybrid Meta-GGA XC Functional m05-2x Heavily Parameterized Hybrid Meta-GGA XC Functional p86_c P86 Correlation (PZ81 LSDA + P86 GGA) pbe PBE GGA Exchange-Correlation Functional pbe-d PBE GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction pbe0 PBE0 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) pw91 PW91 GGA Exchange-Correlation Functional pw91_c PW91 Correlation pw91_x PW91 Parameterized GGA Exchange pw92_c pz81_c PZ81 Correlation svwn SVWN3 (RPA) LSDA Functional s_x Slater LSDA Exchange vwn3rpa_c VWN3 (RPA) LSDA Correlation vwn3_c VWN3 LSDA Correlation vwn5rpa_c VWN5 (RPA) LSDA Correlation vwn5_c VWN5 LSDA Correlation 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 Parameterized Hybrid LRC B97 GGA XC Functional with Dispersion w/ Chai and Head-Gordon Dispersion Correction wblyp BLYP SR-XC Functional (HJS Model) wpbe PBE SR-XC Functional (HJS Model) wpbe0 PBE0 SR-XC Functional (HJS Model) 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) wsvwn LSDA SR-XC Functional ws_x Slater Short-Range LSDA Exchange name calls method in Kallay’s MRCC program 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) Parameters: - name (string) –
'scf' || 'df-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.
- bypass_scf (boolean) –
'on' ||
'off' 
Indicates whether, for name values built atop of scf calculations, the scf step is skipped. Suitable when special steps are taken to get the scf to converge in an explicit preceeding scf step.
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 >>> energy('sapt0-ct',cast_up=True)
>>> # [3] Arbitrary-order MPn calculation >>> energy('mp4')
- name (string) –