Complex sentence: In computational chemistry, NDDO (neglect of diatomic differential overlap) is a formalism that was first introduced by John Pople and it is now the basis of most successful semiempirical methods.
Split into simpler sentences: In computational chemistry, NDDO stands for neglect of diatomic differential overlap. The formalism was first introduced by John Pople and it is now the basis of most successful semiempirical methods.