ATOMIC NUMBER nn IS NOT AVAILABLE...
This error message indicates that the specified element has not been parameterized for the given method. This is a fatal error message. (For MINDO3, an additional test of each pair of elements must be made so that even if the element is available a given pair of elements may not be available.) Switching to a different method may resolve this error. See Table 3.1 and Table 3.2 for a list of elements that have parameters for each semiempirical method.