19.5.6 Natural orbitals


Request to calculate final natural orbitals and write them to record record. The default for record is 2140.2, or what else has been specified on an ORBITAL card, if present. By default, the orbitals are not printed and the hamiltonian is not diagonalized for the new orbitals The following options can be specified (in any order):

Diagonalize the hamiltonian in the basis of the computed natural orbitals and print the configurations and their associated coefficients. This has the same effect as the GPRINT,CIVECTOR directive (see section 6.12. By default, only configurations with coefficients larger than 0.05 are printed. This threshold can be modified using the THRESH (see section 19.8.2) or GTHRESH (see section 6.11) options.

Compute natural orbitals for the specified state. state has the form istate.isym, e.g., 3.2 for the third state in symmetry 2. In contrast to earlier versions, isym refers to the number of the irreducible representation, and not the sequence number of the state symmetry. It is therefore independent of the order in which WF cards are given. The specified state must have been optimized. If STATE is not given and two or more states are averaged, the natural orbitals are calculated with the state-averaged density matrix (default).

Compute natural orbitals for states with the specified spin. ms2 equals $2*S$, i.e., 0 for singlet, 1 for doublet etc. This can be used to together with STATE to select a specific state in case that states of different spin are averaged. If STATE is not specified, the state-averaged density for all states of the given spin is used.

Request to save the civector(s) to the specified record.

Request to save the orbitals to the specified record (same effect as specifying record as first agrument (see above).

Request to print nvirt virtual orbitals in each symmetry. By default, the orbitals are not printed unless the ORBPRINT option (see section 19.8.1 is present or the global GPRINT,ORBITALS (see section 6.12) directive has been given before. The PRINT option on this card applies only to the current orbitals.

Several NATORB, CANORB, and LOCORB cards (for different states) may follow each other. In contrast to earlier versions of MOLPRO the different orbital sets can all be stored in one dump record (but different records still work). See section 4.11 for information about dump records and how specific orbital sets can be requested in a later calculation.

molpro@molpro.net 2018-11-16