$dft functional lhf gridsize 6
With the LHF potential Rydberg series of virtual orbitals can be obtained. To that end, diffuse orbital basis sets have to be used and special grids are required.
gridtype 4
is the most diffuse with special radial scaling;
gridtype 5
is for very good Rydberg orbitals;
gridtype 6
(default in Lhfprep) is the least diffuse,
only for the first Rydberg orbitals.
Only gridsize 3-5 can be used, no multiple grids.
Use test-integ
to check if the selected grid is accurate enough for the
employed basis-set.