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# Optimize

`optimize`(name[, func, mode, dertype, molecule])

  Function to perform a geometry optimization.

  Aliases: | opt()
  Returns: | (float) Total electronic energy of optimized structure in Hartrees.
  PSI variables: |

  - `CURRENT ENERGY`

  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) [manual]
  dcft | density cumulant functional theory [manual]
  mp2 | 2nd-order Moller-Plesset perturbation theory (MP2) [manual]
  df-mp2 | MP2 with density fitting [manual]
  conv-mp2 | conventional MP2 (non-density-fitting) [manual]
  mp2.5 | MP2.5 [manual]
  mp3 | third-order MP perturbation theory [manual]
  omp2 | orbital-optimized second-order MP perturbation theory [manual]
  omp2.5 | orbital-optimized MP2.5 [manual]
  omp3 | orbital-optimized third-order MP perturbation theory [manual]
  ocepa | orbital-optimized coupled electron pair approximation [manual]
  cepa0 | coupled electron pair approximation(0) [manual]
  ccsd | coupled cluster singles and doubles (CCSD) [manual]
  ccsd(t) | CCSD with perturbative triples (CCSD(T)) [manual]
  eom-ccsd | equation of motion (EOM) CCSD [manual]

  name | calls method DFT [manual]
  --- | ---
  b3lyp | B3LYP Hybrid-GGA Exchange-Correlation Functional
  b3lyp-chg | B3LYP Hybrid-GGA Exchange-Correlation Functional w/ Chai and Head-Gordon Dispersion Correction
  b3lyp-d | B3LYP Hybrid-GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction
  b3lyp-d1 | B3LYP Hybrid-GGA Exchange-Correlation Functional w/ Grimme’s -D1 Dispersion Correction
  b3lyp-d3 | B3LYP Hybrid-GGA Exchange-Correlation Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  b3lyp-d3bj | B3LYP Hybrid-GGA Exchange-Correlation Functional w/ Grimme’s -D3 (BJ-damping) 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
  b97-d3 | B97-D Pure-GGA Exchange-Correlation Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  b97-d3bj | B97-D Pure-GGA Exchange-Correlation Functional w/ Grimme’s -D3 (BJ-damping) Dispersion Correction
  blyp | BLYP GGA Exchange-Correlation Functional
  blyp-d | BLYP GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction
  blyp-d1 | B3LYP Hybrid-GGA Exchange-Correlation Functional w/ Grimme’s -D1 Dispersion Correction
  blyp-d3 | BLYP GGA Exchange-Correlation Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  blyp-d3bj | BLYP GGA Exchange-Correlation Functional w/ Grimme’s -D3 (BJ-damping) Dispersion Correction
  bp86 | BP86 GGA Exchange-Correlation Functional
  bp86-d | BP86 GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction
  bp86-d1 | B3LYP Hybrid-GGA Exchange-Correlation Functional w/ Grimme’s -D1 Dispersion Correction
  bp86-d3 | BP86 GGA Exchange-Correlation Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  bp86-d3bj | BP86 GGA Exchange-Correlation Functional w/ Grimme’s -D3 (BJ-damping) Dispersion Correction
  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 Pure-GGA Exchange-Correlation Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  hcth120-d3bj | HCTH120 Pure-GGA Exchange-Correlation Functional w/ Grimme’s -D3 (BJ-damping) Dispersion Correction
  hcth147 | HCTH147 Pure-GGA Exchange-Correlation Functional
  hcth407 | HCTH407 Pure-GGA Exchange-Correlation Functional
  hf+d | w/ Podeszwa and Szalewicz Dispersion Correction
  lyp_c | LYP Correlation
  m05 | Heavily Parameterized Hybrid Meta-GGA XC Functional
  m05-2x | Heavily Parameterized Hybrid Meta-GGA XC Functional
  m05-2x-d3 | Heavily Parameterized Hybrid Meta-GGA XC Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  m05-d3 | Heavily Parameterized Hybrid Meta-GGA XC Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  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
  pbe-d1 | PBE GGA Exchange-Correlation Functional w/ Grimme’s -D1 Dispersion Correction
  pbe-d3 | PBE GGA Exchange-Correlation Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  pbe-d3bj | PBE GGA Exchange-Correlation Functional w/ Grimme’s -D3 (BJ-damping) Dispersion Correction
  pbe0 | PBE0 Hybrid GGA Exchange-Correlation Functional
  pbe0-d | PBE0 Hybrid GGA Exchange-Correlation Functional w/ Grimme’s -D2 Dispersion Correction
  pbe0-d3 | PBE0 Hybrid GGA Exchange-Correlation Functional w/ Grimme’s -D3 (zero-damping) Dispersion Correction
  pbe0-d3bj | PBE0 Hybrid GGA Exchange-Correlation Functional w/ Grimme’s -D3 (BJ-damping) 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 Exchange-Correlation 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 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 (RPA) LSDA Correlation
  vwn3_c | VWN3 LSDA Correlation
  vwn5rpa_c | VWN5 (RPA) LSDA Correlation
  vwn5_c | VWN5 LSDA Correlation
  dldf | Dispersionless Hybrid Meta-GGA XC Functional
  dldf+d | Dispersionless Hybrid Meta-GGA XC Functional w/ Podeszwa and Szalewicz Dispersion Correction
  dldf+d09 | Dispersionless Hybrid Meta-GGA XC Functional w/ Podeszwa and Szalewicz Dispersion Correction

  Warning

  Optimizations where the molecule is specified in Z-matrix format with dummy atoms will result in the geometry being converted to a Cartesian representation.

  Parameters:

  - name (string) –

    `'scf'` || `'df-mp2'` || `'ci5'` || etc.

    First argument, usually unlabeled. Indicates the computational method to be applied to the database. May be any valid argument to `energy()`.

  - func (function) –

    `gradient` || `energy` || `cbs`

    Indicates the type of calculation to be performed on the molecule. The default dertype accesses `'gradient'` or `'energy'`, while `'cbs'` performs a multistage finite difference calculation. If a nested series of python functions is intended (see Function Intercalls), use keyword `opt_func` instead of `func`.

  - mode (string) –

    `'continuous'` || `'sow'` || `'reap'`

    For a finite difference of energies optimization, indicates whether the calculations required to complete the optimization are to be run in one file (`'continuous'`) or are to be farmed out in an embarrassingly parallel fashion (`'sow'`/`'reap'`). For the latter, run an initial job with `'sow'` and follow instructions in its output file.

  - dertype (dertype) –

    `'gradient'` || `'energy'`

    Indicates whether analytic (if available) or finite difference optimization is to be performed.

  - molecule (molecule) –

    `h2o` || etc.

    The target molecule, if not the last molecule defined.

  Examples: |

      >>> # [1] Analytic scf optimization
      >>> optimize('scf')

      >>> # [2] Finite difference mp5 optimization
      >>> opt('mp5')

      >>> # [3] Forced finite difference ccsd optimization
      >>> optimize('ccsd', dertype=1)

For further discussion of geometry optimization, see Sec. Geometry Optimization.

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