The command EADIAB requests the determination of the adiabatic energies as a function of $R$. These are defined by Eq. (6) of the help link which summarizes the close coupling method. The command line syntax can be one of the following:

EADIAB
EADIAB,<jobname>
EADIAB,<jobname>,<nch_max>
EADIAB,<jobname>,<nch_min>,<nch_max>

where

• jobname: the jobname under which the wavefunction information from the previous run is stored, as the file <jobname>.wfu. If missing, the current jobname will be used. The default jobname in Hibridon is job
• nch_min: the ID of the first adiabatic energy for each $R$ to be printed, assuming the adiabatic energies are labeled starting from the lowest one. If missing, the default value 1 will be used.
• nch_max: the ID of the last adiabatic energy for each $R$ to be printed. If missing, the default value 10 will be used. Specifically, if nch_max is set to 0, all adiabatic energies will be printed.

The adiabatic energies will be stored in file <jobname>.eadiab, which is a text file with one header line. Units of $R$ and adiabatic energies used in the file are Bohr and wavenumber, respectively.

⚠️ In order to create the <jobname>.wfu file, the previous run must have been done with the flags WAVEFL and AIRYFL both set .TRUE.. In that run, WRSMAT controls whether information other than the adiabatic energies, e.g. the transformation matrices, will be written to the wfu file. If WRSMAT is set to FALSE, the wfu file will be much smaller but cannot be used for PSI or FLUX calculations.

The only adiabatic energies which are written out are those which correlate adiabatically at large $R$ with the internal states of the collision partners whose rotational angular momenta and additional indices are specified in the arrays JOUT and INDOUT. Specifically, adiabatic energies are given for each channel for which

J(i) = JOUT(i)

and for which the vector element INDOUT(i) corresponds to the quantum number L and the extra index of the desired channel packed into a single array as follows:

INDOUT(i) = sign[IND(i)] x [100 L(i) + | IND(i) | ]

The asymptotic energy ordering of the internal states can be determined by running with the flag BASTST set .TRUE.

⚠️ The adiabatic energies are determined at all values of $R$ lying between RENDLD and RENDAI, with the grid size and spacing controlled by the same parameters which govern the AIRY integration, namely SPAC, FSTFAC, TOLAI, and RINCR.

⚠️ Highly localized avoided crossings of the adiabatic curves often occur. Use of a fine grid in $R$ is the only way to interpret properly the adiabatic energies in these cases.