HP MLIB User's Guide Vol. 2 7th Ed.

Chapter 15 Sparse Eigenvalues and Eigenvectors 1031
Eigenextraction DSEVES
’B’ or ’b’ Generalized symmetric (buckling)
problem Kx = λK
δ
x, with K positive
semi definite and K
δ
possibly
indefinite.
’O’ or ’o’ Ordinary symmetric eigenproblem
Kx = λx.