This directory contains four examples using the FEM_DVR class library that implements Exterior Complex Scaling (ECS) using the Finite Element Discrete Variable Representation numerical methods.

Two examples are for H2 using the accurate potential curve fit of Waech and Bernstein (referenced in the Turner-McCurdy paper below) T. G. Waech R.B. Bernstein, J. Chem. Phys. 46 (1967) 4905.

The Time-independent example reproduces a Figure 2 of Julia Turner and C. William McCurdy, Chemical Physics 71(1982) 127-133 of the resonace wave function for rotational angular momentum j = 17, which has a centrifugal barrier to dissociation that binds metastable states. The complex resonance energy is E_res = (0.004044878419994 -0.000219496448j) hartrees.

The Time-dependent example propagates an initially Gaussian wave packet that starts centered at a value of R just inward of the maximum in the potential V(R) +j(j+1)/2*mu*R^2

There are two examples that read in the files potcurve_CO_CISDT_ccpvDZ.dat and potcurve_CISD_H2_ccpvTZ.dat for finding the vibrational states of CO and H_2, respectively.

Finally there is a 2-electron example using a 2D Hamiltonian and there is an example showing the excitation of a vibrational state from one potential curve to another by a 3 femtosecond UV pulse.

Plotting output from all four examples is written in ./Plot_Output while .dat files are written in this directory. Spectrum.dat contains the eigenvalues of the ECS scaled Hamiltonian.