Abstract
The first‐order quantum corrections to the equations of state of an almost‐classical N‐particle system are calculated to all orders in the particle density by expanding the normalized Wigner distribution function in powers of h 2. In this way one avoids the expansion of the partition function, which has the unsatisfactory property that the correction terms diverge in the thermodynamic limit. Similarly, the first‐order quantum correction to the pair distribution function is derived.