This variable selects the amount of OpenCL device memory that will be used by Octopus to store the states.
A positive number smaller than 1 indicates a fraction of the total
device memory. A number larger than one indicates an absolute
amount of memory in megabytes. A negative number indicates an
amount of memory in megabytes that would be subtracted from
the total device memory.
states/states_elec.F90 : 1342
call parse_variable(namespace, 'StatesCLDeviceMemory', CNST(-512.0), st%d%cl_states_mem)