Basis Subroutine and System Specific Parameters: Collisions of two ¹Sigma Diatomics

System subroutine: sy2mol

Basis subroutine: hiba2mol.f

NTERM: (the number of potential surfaces involved: this should be 1 in this case). This parameter can not be changed

NSYM: interchange symmetry of the included channels

NUMJ: number of different J1/J2 pairs in channel list

J1/J2: vector of length NUMJ containing packed index of rotational quantum number of each molecule with j₁ in the tens digit and j₂ in the ones digit.

For example, if NUMJ = 3, the program expects three J1/J2 values. Suppose these values are, successively, 00, 11, and 02. The calculation will then include all channels with the following pairs of molecular rotational angular momenta:

j₁ = 0, j₂ = 0
j₁ = 1, j₂ = 1
j₁ = 0, j₂ = 2


Note that because of interchange symmetry, the last entry will automatically include all channels with j₁ = 2, j₂ = 0

BROT: rotational constant

DROT: centrifugal distortion constant

HROT: second centrifugal distortion constant


E(j)=B j (j + 1) - D [j (j + 1)]² + H [j (j + 1)]³