issue2071: Modified 2T-MD Cutoff in E-P Coupling

Changes in the source files:

control.f90:

Line 1327: Retrieve elph_cut and check if it is greater than 0 (Subroutine read_ttm).

Line 3965: Set elph_cut in the table (Subroutine initialise_control).

control_output.F90:

Line 1219: Write elph_cut if the cutoff is activated in the output file (Subroutine write_ttm).

old_control.f90:

Line 2603: Add a condition to evaluate elph_cut and activate the cutoff approach (Subroutine read_control).

Line 4451: Implement an evaluation of elph_cut, read the cutoff parameter, and set elph_cut_sq (Subroutine scan_control).

ttm.f90:

Line 121: Initialise logical variable use_elph_cut.

Line 169: Initialise real variables elph_cut and elph_cut_sq.

ttm_track.f90:

Line 600: Evaluate and include only low-energy ions in the temporary estimate and e-ph coupling if the cutoff is activated (ttm_ion_temperature).
This method is described in the article, DOI: 10.1088/1361-648X/ad4941.