  We first consider the recrystallization characteristics of catalysis alloy
and graphite in the process of diamond synthesis under the condition of super
high pressure and high temperature in catalysis method. In the process of
diamond synthesis catalysis metal is plastically deformed by increase of
pressure and then recrystallized as increasing the temperature. As catalysis
metal is recrystallized, the shape of graphite particle is in spherical shape
in the region contacting with the catalyst but in any shape in the opposite
region. In addition, we calculate the electron charge density distribution and
cohesive energies of cementite structure using the first principle method to
investigate the reciprocal interaction between transient metal elements and
carbon atoms in high-temperature catalyst synthesis. After determination of
lattice constant parameters, we obtain the cohesive energy by subtracting the
total energy of the crystal from the summation of total energies of atoms
composing the crystal and dividing it by the number of atoms. Therefore, the
effect of the catalyst on the diamond synthesis is to be analyzed
theoretically.
