Correction Structure Constant Programme COR

The COR is constructed to calculate those extra structure constants which may be used to correct the ASA for approximate treatment of the region between the sphere and the atomic polyhedron, and for the neglect of higher components as described in Sect.6.9. The programme produces and stores on disk or tape a set of correction-term matrices distributed on a suitable grid in the irreducible wedge of the Brillouin zone. Whenever requested the correction matrices may be retrieved by LMTO and used together with the canonical structure constants to set up the corrected LMTO matrices. 

Calculation of the correction structure constants (6.58,8.26) involves reciprocal lattice sumations of spherical Bessel functions which are performed in a straightforward manner. In a typical application COR is executed 158 

The correction constants do not have this convenient property, and they must be calculated for the actual choice of the ratio S /S. Of course this applies only to the cases with two or more inequivalent atoms in the cell. 

The basis input for COR is the basis vectors giving the positions of the atoms in the cell, and the reciprocal-space vectors generated by STR. The basic output of COR is the correction-term structure constants used by LMTO to perform the most accurate band calculations allowed by the present collection of computer programmes. 

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