## Abstract

Accurate "first-principle'" expressions for the excess free energy F_{ex} and internal energy of U_{ex} of the classical one-component plasma (OCP) are obtained. We use the Hubbard-Schofield transformation that maps the OCP Hamiltonian onto the Ising-like Hamiltonian, with coefficients expressed in terms of equilibrium correlation functions of a reference system. We use the ideal gas as a reference system for which all the correlation functions are known. Explicit calculations are performed with the high-order terms in the Ising-like Hamiltonian omitted. For small values of the plasma parameter Γ the Debye-Huckel result for F_{ex} and U_{ex} is recovered. For Γ ≫ 1, these depend linearly on Γ in accordance with the Monte Carlo findings for the OCP. The MC data for the internal energy are reproduced fairly well by the expression for U_{ex} obtained.

Original language | English |
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Pages (from-to) | 489-499 |

Number of pages | 11 |

Journal | Contributions to Plasma Physics |

Volume | 38 |

Issue number | 4 |

DOIs | |

Publication status | Published - 1998 |

Externally published | Yes |