[Pw_forum] Fixing atoms in vc-relax

Dear Sridhar Sadasivam, Fixing atoms by specifying trailing zeros leads to fixing atomic coordinates within the cell, i.e., their fractional coordinates. When doing 'relax' type of calculation, keeping fractional coordinates unchanged is equivalent to keeping Cartesian coordinates the same, thus

[Pw_forum] Technique for converging Ecut and K-points?

Dear Ben, I would also like to contribute my 5 cents to the discussion. There are two main questions to answer prior to any convergence study. 1) What quantity is of interest? If you can answer this question, you can save a lot of time and computational resources, because different quantities

[Pw_forum] Problem in vc-relax, radial FFT

Dear Ali, > > During convergence, the error was : Not enough space allocated for radial > FFT: try restarting with a larger cell_factor > . > So my question is : What is the real problem in my input ? > the real problem in your input is that the initial lattice parameters are way too far from