采用全势的线性Muffin tin轨道 (FP LMTO)方法对铁在高压下的结构和磁性进行了系统的研究 .对铁存在的三种结构bcc,fcc和hcp分别以三种磁性耦合机理在很宽的体积范围内进行了计算 ,得到系统的总能、磁矩随体积变化的关系 ;导出了压强与体积、体弹性模量与体积的关系曲线 ;讨论了各相在不同范围内的稳定性 ;估算了α→ε相之间的转变压强 ;并把得到的结果与实验进行了比较 ,证明所得到的结果与实验是一致的 The structure and magnetism of iron under high pressure were systematically investigated by the full potential linear Muffin tin orbit (FP LMTO) method.The three structures of iron, bcc, fcc and hcp, respectively, were characterized by three magnetic coupling mechanisms The relationship between the total energy and the magnetic moment of the system with volume change was deduced. The relation curves of pressure and volume, body elastic modulus and volume were derived. The stability of each phase in different range was discussed. The transformation pressure between α and ε phases was estimated. The obtained results were compared with the experimental ones, and the results obtained were consistent with the experiments