A theoretical study of spin level crossing induced by an external magnetic field of ring molecule magnet models

The dependence of the magnetization of model systems on an external magnetic field has been investigated. An ab initio path integral Monte Carlo method is used to study the spin level crossing phenomena of molecules with ring structures such as those in the ferric wheel [Fe(OMe)2(O2CCH2Cl)]10. The ab initio treatment is essential to calculate the magnetization in a system with a large contribution from next-neighbor interactions. A possible use as a molecular device for switching or molecular recognition is suggested.