README: Atoms and Diatomics

• Perform a basic Kohn-Sham DFT calculation on individual atoms up to Neon.

• Highlights some of the primary usages of pyCADMium, especially the molecule specification.

• Some of the options to define a system are self-explanatory. For example, the value Z_x assigns the nuclear charge, while pol states whether or not we are performing a spin unrestricted calculation.

• Assigning the electronic structure can get a bit finicky. To do this, one must know the system’s orbital configuration. That is the number of orbitals for a respective angular momentum. If only one bracket is in the definition, only s orbitals are present; If two brackets are present, p orbitals are present, etc. Additionally, if the brackets have one component, alpha_i and beta_i orbital are identical; if two values are present, one corresponds to alpha and the other to beta electrons.

• If pol = 1, you must assign 2 electrons per orbital. On the other hand, if pol = 2, you must set 1 electron per orbital.

• Even if there is only one atom in the system, you still have to specify a charge of `Z_x = 0’.

• This notebook helps perform benchmarks for different functionals using a fine grid.