Atk performance !

[Ragnar]

Hello everyone !
I did some calculations with Atomistic toolkit and Quantum espresso and i noticed the huge difference if terms of time and complexity. Im wondering what is the deep reason behind this, physically meaning ?
I did the same calculations which requires a huge vacuum ( molecule configuration ) with the same approximation for both codes .
thank you a lot ..

[Jess Wellendorff]

Can you provide the details of the difference you find?

[Ragnar]

Thank you for your reply Jess Welledorff
For example i ran the calculations with ATK and it takes over 7 hours , my computer works fine  but when i tried to run the calculations over again with quantum espresso it takes more than 2 days ( the same imput file ) then the computer becomes very hard to be used
thank you

[Jess Wellendorff]

OK, so what you find is that ATK is much faster than Quantum ESPRESSO for a molecule configuration with a huge vacuum, right? In general, the ATK LCAO basis set is much better suited for non-periodic (molecular) calculations than the plane waves used by ESPRESSO. Also, different pseudopotentials are most likely used in your calculations.