In order to interpret the large shift between the observed high spin fraction and the so-called molar high spinfraction in the Mossbauer study on gradual spin transition complexes, we reveal numerically that the effectsfrom residual phases in the substance should be considered in the correction by Debye-Waller factors. This resultshows that similar Debye-Waller factors in high and low spin states agree well with the conclusion of experimentalinvestigations for such gradual spin transition complexes.