Dear users !<br> I tried to calculate bulk energy and equilibrium lattice parameters of some system using vc-relax calculation. I done the calculation using both the algorithm naming (1)damped dynamics means 'ion_dynamics' as "damp" and 'cell_dynamics' as "damp-w" (2) BFGS means 'ion_dynamics' as "bfgs" and 'cell_dynamics' as"bfgs" . I have changed only these two things in these two alogorithm. But first case was taking very much time(~2hours) and wasnt convergence after 200 ionic steps whereas in the second case it took very less time (6-7 minutes) to get equilbrium bulk structure. Can anybody please explain me what is the thing which is making so much differnce?<br>
Sincere thanks in advance,<br>Mohnish<br clear="all"><br>-- <br>Mohnish Pandey<br>Y6262,4th Year Undergraduate,<br>Department of Chemical Engineering,<br>IIT KANPUR<br>