transqt(1)

NAME
transqt - transforms one and two electron integrals over symmetry orbitals into integrals over molecular orbitals.

DESCRIPTION
The program transqt reads molecular orbital coefficients from and uses them to transform the one and two electron integrals contained in , , , and to integrals over molecular orbitals. No integrals involving frozen occupied and unoccupied orbitals (as determined from user input) are transformed. As a consequence, the program must be re-run whenever the user-input frozen orbital arrays are changed. The program uses a straightforward four single-index transformation algorithm, modified to use matrix multiplications for each quarter-transform. Additionally, restricted transformations have been implemented when an MP2 or MP2-R12/A energy is desired. Further, the program is capable of backtransforming the Lagrangian and one- and two-particle density matrices from correlated calculations. This assumes that the terms involving core orbitals are present, but those involving frozen virtual orbitals are not.

REFERENCES

General integral transformation methods:

1.  S. Wilson, "Four-Index Transformations," in Methods in Computationsl Chemistry, Vol. 1, S. Wilson, ed., Plenum Press, 1987.

TRANSQT references:

1.  C. D. Sherrill, "Computational Algorithms for Large-Scale Full and Multi-Reference Configuration Interaction Wavefunctions", Ph.D. Dissertation, University of Georgia, 1996.

INPUT OPTIONS

The following command-line options are available:

-quiet
    This gives the same result as PRINT=0.

-backtr
    This runs a back-transformation and has the same effect as BACKTRANS=TRUE.

-mp2r12a type
    This tells TRANSQT to transform non-standard two-electron integrals required in MP2-R12/A calculations. Program CR12INTS must be run prior to the transformation. type should take values from 0 to 2, where 0 refers to regular ERIs and one-electron integrals, 1 - to two-electron integrals over the r12 operator, and 2 to two-electron integrals over the [r12,T1] operator. Thus, to obtain a complete set of integrals TRANSQT needs to be run three times.

Additional input is read from the file The following keywords are valid:

BACKTRANS = boolean
    This is set to TRUE for a back-transformation of the Lagrangian and the one- and two-particle density matrices from the MO basis to the AO basis. It is assumed that these quantities are given in terms of the correlated orbital order. TRANSQT will rearrange them into the Pitzer order but with frozen virtuals at the top (this occurs during the pre-sort for the two-pdm).

CHECK_C_ORTHONORM = boolean
    If TRUE, then check the orthonormality of the SCF coefficient matrix.

MEMORY = (real MB)
    Gives the amount of core memory to be used, in megabytes.

WFN = string
    This is the type of wavefunction ultimately desired. If the value is set to MP2, then only a restricted transformation which produces integrals necessary for the evaluation of the MP2 energy is performed. Otherwise, a full transformation is carried out. The default is CCSD.

PRINT = integer
    Determines the verbosity of the printing information. A print value of 0 gives minimal information, while 5 gives debugging information (do NOT use print levels above 3 for more than 20 basis functions). The default is 0.

FROZEN_DOCC = integer_vector
    Array giving the number of doubly occupied orbitals to be frozen per irreducible representation, using Cotton ordering. The default is a zero array.

FROZEN_UOCC = integer_vector
    Array giving the number of virtual molecular orbitals per irrep to be deleted from the transformed integrals. The default is a zero array.

DELETE_AO = boolean
    If TRUE, then the AO integrals will be deleted after the transformation. The default is TRUE.

DELETE_TPDM = boolean
    If TRUE, then the MO-basis two-particle density matrix will be deleted after a back-transformation. The default is TRUE.

FREEZE_CORE = boolean
    If this is true then the transformed one- and two-electron integrals involving frozen core orbitals will not be obtained or written out. The transformed one-electron integrals will incorporate the effects of the frozen electrons (i.e. the one-electron operator h(i) will become the frozen core operator h'(i)), and the frozen core energy will be obtained (it is written out as the first word of the one-electron integral output file). If FREEZE_CORE is false, then the frozen core orbitals will be included in the transformation, and the frozen core energy will be set to zero.

MAX_BUCKETS = integer
    Maximum number of buckets to use during the Yoshimine sort. The default is 199.

MOORDER = integer_vector
    This specifies a molecular orbital reordering vector. It will only be used if REORDER = YES. This vector contains first the ordering for the orbitals in the first irreducible representation and then the second and so on. The first orbital of each irreducible representation is numbered 1. There is no default. This reordering affects the SCF coefficient matrix BEFORE the transformation; the post-transform order is given by a different array.

REORDER = boolean
    The molecular orbitals will be reordered if this is true, in which case, the MOORDER parameter must be present. The default is false. This has nothing to do with the reordering done AFTER the transformation (to a more convenient order for correlated procedures).

PRINT_MOS = boolean
    If TRUE, the SCF coefficient matrix is written to output. The default is FALSE.

PRINT_REORDER = boolean
    If true prints reordering array which maps Pitzer-ordered orbitals to correlated order. This is not the same as the MOORDER array, which has to do with reordering BEFORE the transformation.

S_FILE = integer
    If USE_IWL=TRUE, this gives the file number for the overlap integrals. The default is 35.

T_FILE = integer
    If USE_IWL=TRUE, this gives the file number for the kinetic energy integrals. The default is 36.

V_FILE = integer
    If USE_IWL=TRUE, this gives the file number for the nuclear attraction integrals. The default is 37.

AO_TEI_FILE = integer
    This gives the file number for the SO two-electron integrals to be read in for transforming. The default is 33.

J_FILE = integer
    This gives the file number for the intermediate file containing the half-transformed two-electron integrals. The default value is 91.

KEEP_J = boolean
    If this is true then the half-transformed integrals will not be deleted when the transformation is complete. The default is FALSE.

M_FILE = integer
    This gives the file number for the intermediate file containing the fully transformed two-electron integrals. The default value is 72.

FIRST_TMP_FILE = integer
    Gives the number of the first temp file to be used during the Yoshimine sorts. Default is 100.

LAG_IN_FILE = integer
    This is the unit number for the MO Lagrangian which is to be read in during backtransformations. It is expected that the Lagrangian is stored on disk in binary format in a matrix of dimensions (nmo - nfzv)*(nmo-nfzv). The Lagrangian is symmetrized and then backtransformed and written after the AO one-particle density matrix in OPDM_OUT_FILE.

OPDM_IN_FILE = integer
    This is the unit number for the MO one-particle density matrix to be read in during backtransformations. The one-pdm is in binary format and has dimensions nmo by nmo.

OPDM_OUT_FILE = integer
    This is the unit number to which the AO one-particle density matrix will be written out. Only the lower triangle is written. The AO Lagrangian will be written just after the AO one-pdm, again in lower-triangle format.

PRESORT_FILE = integer
    This gives the file number for the intermediate file containing the presorted SO-basis two-electron integrals. The default is 41.

KEEP_PRESORT = boolean
    If this is true then the presorted SO-basis two-electron integrals will not be deleted when the transformation is complete. The default is FALSE.

SORTED_OEI_FILE = integer
    This gives the file number for the final, sorted one electron integrals. The default is 71.

SORTED_TEI_FILE = integer
    This gives the file number for the final, sorted two electron integrals. The default is 72.

TPDM_ADD_REF = boolean
    If TRUE, then the program will automatically add the contributions of the single determinant reference to the two-particle density matrix. The default is TRUE for wfn = QVCCD and FALSE otherwise.

TPDM_FILE = integer
    This gives the file number for the two-particle density matrix which is to be back-transformed if BACKTRANS=TRUE. The default is 77.

TOLERANCE = integer
    This gives the exponent of the cutoff value for the elimination of two-electron integrals from the list of those written to disk. The default is 14, giving a cutoff of 1e-14.

PRINT_TE_INTEGRALS = boolean
    If this is true then the fully-transformed two-electron integrals will be written to The default is FALSE, and this should not be set to TRUE for any but the smallest basis sets (e.g. fewer than 10 functions).

PRINT_OE_INTEGRALS = boolean
    If this is true then the fully-transformed one-electron integrals will be written to The default is FALSE, and this should not be set to true for any but very small basis sets (e.g. fewer than 20 functions).