ASE supplies a powerful and comfortable interface with VASP. Today, I want to set the mass of element H from 1 to 2(deuterium)，which can be achieved by setting the parameter “pomass”. But it seems that in ase method cal.set(pomass=x), x can only be a float number. I want set cal.set(pomass=63.546 12.011 2.000 16.000) because there are 4 element types in system and H is the third one but it gave an error.
So how can i set pomass value in ase if my system have more than two element types?
Thank you for your help!