# CCSORT

Sorts integrals for efficiency. Called before (non density-fitted) MP2 and coupled cluster computations.

## General

### AO_BASIS

> The algorithm to use for the terms

> - Type: string
> - Possible Values: NONE, DISK, DIRECT
> - Default: NONE

### CACHELEVEL

> Cacheing level for libdpd governing the storage of amplitudes, integrals, and intermediates in the CC procedure. A value of 0 retains no quantities in cache, while a level of 6 attempts to store all quantities in cache. For particularly large calculations, a value of 0 may help with certain types of memory problems. The default is 2, which means that all four-index quantites with up to two virtual-orbital indices (e.g., integrals) may be held in the cache.

> - Type: integer
> - Default: 2

### EOM_REFERENCE

> Reference wavefunction type for EOM computations

> - Type: string
> - Default: RHF

### INTS_TOLERANCE

> Minimum absolute value below which integrals are neglected.

> - Type: conv double
> - Default: 1e-14

### KEEP_OEIFILE

> Do retain the input one-electron integrals?

> - Type: boolean
> - Default: false

### KEEP_TEIFILE

> Do retain the input two-electron integrals?

> - Type: boolean
> - Default: false

### LOCAL

> Do simulate the effects of local correlation techniques?

> - Type: boolean
> - Default: false

### LOCAL_CORE_CUTOFF

> Local core cutoff value

> - Type: double
> - Default: 0.05

### LOCAL_CPHF_CUTOFF

> Cutoff value for local-coupled-perturbed-Hartree-Fock

> - Type: double
> - Default: 0.10

### LOCAL_CUTOFF

> Value (always between one and zero) for the Broughton-Pulay completeness check used to contruct orbital domains for local-CC calculations. See J. Broughton and P. Pulay, J. Comp. Chem. 14, 736-740 (1993) and C. Hampel and H.-J. Werner, J. Chem. Phys. 104, 6286-6297 (1996).

> - Type: double
> - Default: 0.02

### LOCAL_DOMAIN_MAG

> Do generate magnetic-field CPHF solutions for local-CC?

> - Type: boolean
> - Default: false

### LOCAL_DOMAIN_POLAR

> Do use augment domains with polarized orbitals?

> - Type: boolean
> - Default: false

### LOCAL_DOMAIN_SEP

> - Type: boolean
> - Default: false

### LOCAL_FILTER_SINGLES

> Do apply local filtering to single excitation amplitudes?

> - Type: boolean
> - Default: false

### LOCAL_METHOD

> Type of local-CCSD scheme to be simulated. `WERNER` (unique avaliable option) selects the method developed by H.-J. Werner and co-workers.

> - Type: string
> - Default: WERNER

### LOCAL_PAIRDEF

> Definition of local pair domains, unique avaliable option is BP, Boughton-Pulay.

> - Type: string
> - Default: BP

### LOCAL_WEAKP

> Desired treatment of “weak pairs” in the local-CCSD method. The value of `NONE` (unique avaliable option) treats weak pairs in the same manner as strong pairs.

> - Type: string
> - Default: NONE

### OMEGA

> Energy of applied field [au] for dynamic properties

> - Type: array
> - Default: No Default

### PROPERTY

> The response property desired. The unique acceptable values is `POLARIZABILITY` for dipole-polarizabilitie.

> - Type: string
> - Default: POLARIZABILITY

### REFERENCE

> Reference wavefunction type

> - Type: string
> - Default: RHF

### SEMICANONICAL

> Convert ROHF MOs to semicanonical MOs

> - Type: boolean
> - Default: true

## Expert

### WFN

> Wavefunction type

> - Type: string
> - Default: No Default