Volume change in some substitutional alloys using Morse potential function

Volume changes in some low-concentration substitution alloys are calculated using the Morse potential function. The potential parameters for the unlike interactions are calculated using a simple interpolation formula. The relaxation of the distant ions is calculated in a consistent way so that both the 'force balance' and 'energy minimum' conditions are satisfied simultaneously. It is observed that the simple model predicts values which are in good agreement with the experimental values in most cases. But a major discrepancy is found to occur in two cases where silver is substituted in copper and lithium.