VCA Utility fails with the interpolation scheme

[Javier Junquera]

The utility to mix pseudo potentials and generate an alchemical pseudopotential fails with the new interpolation routines if the maximum radial point in the two parent pseudo potentials is not the same.

The message is:

evaluate_spline/find_interval ERROR: x out of range
evaluate_spline/find_interval ERROR: x out of range

I have tried to mix the pseudo of O (maximum radius in the psf file = 119.468873521 a.u.) with F (maximum radius in the psf file = 118.839412280 a.u.)

When it tries to interpolate some radial functions, the subroutine find_interval (defined in interpolation.f90 of the source directory), takes the radius of the first pseudo (O) and checks whether it is in the range between the minimum and the maximum values of the second pseudo (F). Since it is out of the range, it crashes.

This bug has been obtained in the trunk. It does not occur in trunk-426, where this subroutine interpolation.f90 was not defined.