References

Calculation of mineral unit cell contents: FORTRAN computer programme A COMPUTER programme for the calculation of cell contents of such minerals as micas, hornblendes, olivines, feldspars, pyroxenes, and garnets has been developed for the IBM 1620 computer. From the basic chemical analysis the cell content is recalculated on the basis of 24 oxygen atoms into the form: (Si,A1,Fe"',Ti)s(A1,Fe'",Fe",Ti,Mg,Mn)x(Na,K,Ca)~(O,OH,F)24 The programme may be easily adapted for groups in which OH is zero by dividing the result calculated to 024 by 6 (olivines), 3 (feldspars), 8 (pyroxenes), or 4 (garnets), or by altering one card in the source pro-gramme. The sole restriction is that not more than 9999 data cards may be processed at once. Floating point arithmetic isused throughout, the atomic ratios in the unit cell are corrected to 0-01. The programme is written in FORTRAN II. The programme execution time is less than 5