Function to perform a geometry optimization.
Aliases :  opt() 

Returns:  (float) Total electronic energy of optimized structure in Hartrees. 
Psi variables: 
Note
Analytic gradients area available for all methods in the table below. Optimizations with other methods in the energy table proceed by finite differences.
name  calls method 

scf  Hartree–Fock (HF) or density functional theory (DFT) 
dcft  density cumulant functional theory 
omp2  orbitaloptimized second order Moller–Plesset perturbation theory 
mp2  2ndorder MollerPlesset perturbation theory (MP2) 
dfmp2  MP2 with density fitting 
convmp2  conventional MP2 (nondensityfitting) 
ccsd  coupled cluster singles and doubles (CCSD) 
ccsd(t)  CCSD with perturbative triples 
eomccsd  equation of motion (EOM) CCSD 
name  calls method 

b3lyp  B3LYP HybridGGA ExchangeCorrelation Functional 
b3lypchg  B3LYP HybridGGA ExchangeCorrelation Functional w/ Chai and HeadGordon Dispersion Correction 
b3lypd  B3LYP HybridGGA ExchangeCorrelation Functional w/ Grimme’s D2 Dispersion Correction 
b3lypd1  B3LYP HybridGGA ExchangeCorrelation Functional w/ Grimme’s D1 Dispersion Correction 
b3lypd3  B3LYP HybridGGA ExchangeCorrelation Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
b3lypd3bj  B3LYP HybridGGA ExchangeCorrelation Functional w/ Grimme’s D3 (BJdamping) Dispersion Correction 
b3_x  Becke88 GGA Exchange (B3LYP weighting) 
b88_x  Becke88 GGA Exchange 
b970  B970 HybridGGA ExchangeCorrelation Functional 
b971  B971 HybridGGA ExchangeCorrelation Functional 
b972  B972 HybridGGA ExchangeCorrelation Functional 
b97d  B97D PureGGA ExchangeCorrelation Functional w/ Grimme’s D2 Dispersion Correction 
b97d3  B97D PureGGA ExchangeCorrelation Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
b97d3bj  B97D PureGGA ExchangeCorrelation Functional w/ Grimme’s D3 (BJdamping) Dispersion Correction 
blyp  BLYP GGA ExchangeCorrelation Functional 
blypd  BLYP GGA ExchangeCorrelation Functional w/ Grimme’s D2 Dispersion Correction 
blypd1  B3LYP HybridGGA ExchangeCorrelation Functional w/ Grimme’s D1 Dispersion Correction 
blypd3  BLYP GGA ExchangeCorrelation Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
blypd3bj  BLYP GGA ExchangeCorrelation Functional w/ Grimme’s D3 (BJdamping) Dispersion Correction 
bp86  BP86 GGA ExchangeCorrelation Functional 
bp86d  BP86 GGA ExchangeCorrelation Functional w/ Grimme’s D2 Dispersion Correction 
bp86d1  B3LYP HybridGGA ExchangeCorrelation Functional w/ Grimme’s D1 Dispersion Correction 
bp86d3  BP86 GGA ExchangeCorrelation Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
bp86d3bj  BP86 GGA ExchangeCorrelation Functional w/ Grimme’s D3 (BJdamping) Dispersion Correction 
ft97  FT97 GGA ExchangeCorrelation Functional 
ft97b_x  Filitov and Theil 1997 Exchange 
ft97_c  FT97 Correlation (Involves Ei functions) 
hcth  HCTH PureGGA ExchangeCorrelation Functional 
hcth120  HCTH120 PureGGA ExchangeCorrelation Functional 
hcth120d3  HCTH120 PureGGA ExchangeCorrelation Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
hcth120d3bj  HCTH120 PureGGA ExchangeCorrelation Functional w/ Grimme’s D3 (BJdamping) Dispersion Correction 
hcth147  HCTH147 PureGGA ExchangeCorrelation Functional 
hcth407  HCTH407 PureGGA ExchangeCorrelation Functional 
hf+d  w/ Podeszwa and Szalewicz Dispersion Correction 
lyp_c  LYP Correlation 
m05  Heavily Parameterized Hybrid MetaGGA XC Functional 
m052x  Heavily Parameterized Hybrid MetaGGA XC Functional 
m052xd3  Heavily Parameterized Hybrid MetaGGA XC Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
m05d3  Heavily Parameterized Hybrid MetaGGA XC Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
p86_c  P86 Correlation (PZ81 LSDA + P86 GGA) 
pbe  PBE GGA ExchangeCorrelation Functional 
pbed  PBE GGA ExchangeCorrelation Functional w/ Grimme’s D2 Dispersion Correction 
pbed1  PBE GGA ExchangeCorrelation Functional w/ Grimme’s D1 Dispersion Correction 
pbed3  PBE GGA ExchangeCorrelation Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
pbed3bj  PBE GGA ExchangeCorrelation Functional w/ Grimme’s D3 (BJdamping) Dispersion Correction 
pbe0  PBE0 Hybrid GGA ExchangeCorrelation Functional 
pbe0d  PBE0 Hybrid GGA ExchangeCorrelation Functional w/ Grimme’s D2 Dispersion Correction 
pbe0d3  PBE0 Hybrid GGA ExchangeCorrelation Functional w/ Grimme’s D3 (zerodamping) Dispersion Correction 
pbe0d3bj  PBE0 Hybrid GGA ExchangeCorrelation Functional w/ Grimme’s D3 (BJdamping) Dispersion Correction 
pbesol_x  PBEsol GGA Exchange Hole (Parameter Free) 
pbe_c  PBE Correlation 
pbe_x  PBE GGA Exchange Hole (Parameter Free) 
pw91  PW91 GGA ExchangeCorrelation Functional 
pw91_c  PW91 Correlation 
pw91_x  PW91 Parameterized GGA Exchange 
pw92_c  
pz81_c  PZ81 Correlation 
rpbe_x  RPBE GGA Exchange Hole (Parameter Free) 
sogga  Second Order GGA ExchangeCorrelation Functional 
sogga_x  Second Order GGA Exchange Hole (Parameter Free) 
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 
dldf  Dispersionless Hybrid MetaGGA XC Functional 
dldf+d  Dispersionless Hybrid MetaGGA XC Functional w/ Podeszwa and Szalewicz Dispersion Correction 
dldf+d09  Dispersionless Hybrid MetaGGA XC Functional w/ Podeszwa and Szalewicz Dispersion Correction 
wb88_x  B88 ShortRange GGA Exchange (HJS Model) 
wb97  Parameterized LRC B97 GGA XC Functional 
wb97x  Parameterized Hybrid LRC B97 GGA XC Functional 
wb97xd  Parameterized Hybrid LRC B97 GGA XC Functional with Dispersion w/ Chai and HeadGordon Dispersion Correction 
wblyp  BLYP SRXC Functional (HJS Model) 
wpbe  PBE SRXC Functional (HJS Model) 
wpbe0  PBE0 SRXC Functional (HJS Model) 
wpbe_x  PBE ShortRange GGA Exchange (HJS Model) 
wpbesol  PBEsol SRXC Functional (HJS Model) 
wpbesol0  PBEsol0 SRXC Functional (HJS Model) 
wpbesol_x  PBEsol ShortRange GGA Exchange (HJS Model) 
wsvwn  LSDA SRXC Functional 
ws_x  Slater ShortRange LSDA Exchange 
Warning
For the present, file intco.dat is lodged in the submission directory and defines the internal coordinates for an optimization. Thus, it is unsafe to run multiple optimizations from a single directory. Also, intco.dat can linger, so, unless you’ve deliberately constructed it, be sure to clear it out before starting a new optimization.
Warning
Optimizations where the molecule is specified in Zmatrix format with dummy atoms will result in the geometry being converted to a Cartesian representation.
Parameters: 


Examples : 
>>> # [1] Analytic scf optimization
>>> optimize('scf')
>>> # [2] Finite difference mp3 optimization
>>> opt('mp3')
>>> # [3] Forced finite difference ccsd optimization
>>> optimize('ccsd', dertype=1)
For further discussion of geometry optimization, see Sec. Geometry Optimization.