These programs which use the subroutine DPI.C are used to calculate doublet pi energies and intensities with one nuclear spin using a Hund's case (a).
| Linear Pi States: | [Q] | ||||
| J + 1/2 | W + 1/2 | l | v | F | [19] |
| J + 1/2 | W + 1/2 | l | v | - | [19] |
| J + 1/2 | W + 1/2 | l | F | - | [8] |
| J + 1/2 | W + 1/2 | l | - | - | [8] |
The field QNFMT in cat file can be regarded as having 3 sub-fields: QFMT = Q*100 + H*10 + NQN, in which NQN is the number of quanta per state, H is a binary code the existence of half integer quanta for F, and Q is the number in square brackets in the table above. The least significant bit of H refers to the F quantum number and is 1 if F is half integer. Th quantum number l has a sign for the inversion parity, for e levels the parity is (-1)J+1/2, while for f levels the parity is opposite.
QN = 12 integer field of quantum numbers. Interpreted in a multiple I3 format as the quantum numbers for the line (upper quanta first, followed immediately by lower quanta). Unused fields can be used for annotation. The entire field is printed in file.fit
FREQ = frequency in MHz or wavenumbers
ERR = experimental error. Minus sign means that the frequency and error are in units of wavenumbers. FREQ and ERR will be converted internally to units of MHz.
WT = relative weight of line within a blend (normalized to unity by program)
notes: If an end-of-file is encountered before all the lines are read in, NLINE is set to the number read to that point. If successive lines have the same frequency, the lines will be treated as a blend and derivatives will be averaged using WT/ERR. Any lines with format errors will be ignored.
The freeform input begins in column 37 and extends to the end of the line. See the notes at the end of the next section for more on the freeform input.
line 1: title
line 2 [freeform]: NPAR, NLINE, NITR, NXPAR, THRESH , ERRTST,FRAC, CAL
NPAR = maximum number of parametersNLINE = maximum number of lines
NITR = maximum number of iterations
NXPAR = number of parameters to exclude from end of list when fitting special lines (see notes)
THRESH = initial Marquardt-Levenburg parameter
ERRTST = maximum [(obs-calc)/error]
FRAC = fractional importance of variance
CAL = scaling for infrared line frequencies (only NPAR used by CALCAT)
Option information on line 3: SPIND, NVIB
SPIND = degeneracy of nuclear spinNVIB = number of vibrations
Parameter lines [freeform]: IDPAR, PAR, ERPAR / LABEL
where IDPAR is a parameter identifier, PAR is the parameter value, ERPAR is the parameter uncertainty, LABEL is a parameter label (10 characters are used) that is delimited by /. If the sign of IDPAR is negative, DPFIT constrains the ratio of this parameter to the previous parameter to a fixed value during the fit.
If NVIB > 1, IDPAR = IV + 100 * IDPAR0, where IV is the vibrational or electronic quantum number. If NVIB = 1, IDPAR = IDPAR0. There are no matrix elements defined connecting the vibrational states.PARAMETER identifiers (IDPAR0) are:
| IDPAR0 | Parameter |
| 1 | A |
| 2 | AJ |
| 3 | AH |
| 4 | B + q / 2 |
| 5 | D |
| 6 | H |
| 7 | p |
| 8 | q |
| 9 | pD |
| 10 | qD |
| 11 | c1 = 0.5 * [a - (b+c) / 2] |
| 12 | c1 = d / 2 |
| 13 | c3 = 1.5 * [a + (b+c) / 2] |
| 14 | c4 |
| 15 | c5 |
| 16 | c6 |
| 17 | c7 |
| 18 | c8 |
| 19 | c9 |
| 20 | z1 = eqQ1 for W = 1/2 |
| 21 | z2 = eqQ1 for W = 3/2 |
| 22 | z3 = - eQq2 / 2 |
| 23 | z4 |
| 24 | z5 |
| 25 | z6 |
| 26 | z7 |
| 27 | g |
line (n+1)-end [8F10.6]: ( ( V(i,j),j=i,NPAR ) ,i=1,NPAR )
V = Choleski decomposition of the correlation matrix, optional for file.parTOP
line 2 [freeform]: FLAGS,TAG,QROT,FBGN,FEND,STR0,STR1,FQLIM,TEMP
FLAGS = IRFLG*1000+OUTFLG*100+STRFLG*10+EGYFLG
IRFLG = 1 if constants are in wavenumbers
OUTFLG = 0 for short form file.out
STRFLG = 1 to enable file.str output
STRFLG = 2 to enable file.str output and print separate entries for each dipole
EGYFLG 0 to enable file.egy energy listing
EGYFLG= 2,4 to enable file.egy derivative listing
EGYFLG = 3,4 to enable file.egy eigenvector listing
EGYFLG 4 to dump Hamiltonian with no diagonalization
QROT = partition function for TEMP
FBGN = beginning integer F quantum (round up)
FEND = ending integer F quantum (round up)
STR0,STR1 = log strength cutoffs
FQLIM = frequency limit in GHz
TEMP = temperature for intensity calculation in degrees K (default is 300K)
line 3-end [freeform]: IDIP,DIPOLE
IDIP is coded in decimal digit form according to the format V2*100+ V1DIPOLE = dipole value
[F13.4,2F8.4,I2,F10.4,I3,I7,I4,12I2]: FREQ,ERR,LGINT,DR,ELO,GUP,TAG,QNFMT,QN
FREQ = Frequency of the line
ERR = Estimated or experimental error (999.9999 indicates error is larger)
LGINT = Base 10 logarithm of the integrated intensity in units of nm2 MHz
DR = Degrees of freedom in the rotational partition function (0 for atoms, 2 for linear molecules, and 3 for nonlinear molecules)
ELO = Lower state energy in wavenumbers
GUP = Upper state degeneracy
TAG = Species tag or molecular identifier. A negative value flags that the line frequency has been measured in the laboratory. The absolute value of TAG is then the species tag (as given in line 2 of file.int above) and ERR is the reported experimental error.
QNFMT = Identifies the format of the quantum numbers given in the field QN.
QN(12)= Quantum numbers coded according to QNFMT. Upper state quanta start in character 1. Lower state quanta start in character 14. Unused quanta are blank, quanta whose magnitude is larger than 99 or smaller than –9 are shown with alphabetic characters or **. Quanta between -10 and -19 are shown as a0 through a9. Similarly, -20 is b0, etc., up to -259, which is shown as z9. Quanta between 100 and 109 are shown as A0 through A9. Similarly, 110 is B0, etc., up to 359, which is shown as Z9.TOP
FREQ = Frequency of the line
DIPOLE= Reduced matrix element of the transition dipole
QNFMT = Identifies the format of the quantum numbers given in the field QN.
QN(12) = Quantum numbers coded according to QNFMT. Upper state quanta start in character 1. Lower state quanta start in character 14. Unused quanta are blank, quanta whose magnitude is larger than 99 or smaller than –9 are shown with alphabetic characters or **. Quanta between -10 and -19 are shown as a0 through a9. Similarly, -20 is b0, etc., up to -259, which is shown as z9. Quanta between 100 and 109 are shown as A0 through A9. Similarly, 110 is B0, etc., up to 359, which is shown as Z9.
ITEM = identifies number of dipole
IBLK = Internal Hamiltonian block number
INDX = Internal index Hamiltonian block
EGY = Energy in wavenumbers
ERR = Expected error of the energy in wavenumbers
PMIX = mixing coefficient
QN(6)= Quantum numbers for the stateTOP
The identity of the files are: