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Diffstat (limited to 'source/know/concept/grand-canonical-ensemble')
-rw-r--r-- | source/know/concept/grand-canonical-ensemble/index.md | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/source/know/concept/grand-canonical-ensemble/index.md b/source/know/concept/grand-canonical-ensemble/index.md index 4f66fd9..62ca896 100644 --- a/source/know/concept/grand-canonical-ensemble/index.md +++ b/source/know/concept/grand-canonical-ensemble/index.md @@ -11,18 +11,18 @@ layout: "concept" The **grand canonical ensemble** or **μVT ensemble** extends the [canonical ensemble](/know/concept/canonical-ensemble/) -by allowing the exchange of both energy $U$ and particles $N$ +by allowing the exchange of both energy $$U$$ and particles $$N$$ with an external reservoir, so that the conserved state functions are -the temperature $T$, the volume $V$, and the chemical potential $\mu$. +the temperature $$T$$, the volume $$V$$, and the chemical potential $$\mu$$. The derivation is practically identical to that of the canonical ensemble. -We refer to the system of interest as $A$, -and the reservoir as $B$. -In total, $A\!+\!B$ has energy $U$ and population $N$. +We refer to the system of interest as $$A$$, +and the reservoir as $$B$$. +In total, $$A\!+\!B$$ has energy $$U$$ and population $$N$$. -Let $c_B(U_B)$ be the number of $B$-microstates with energy $U_B$. -Then the probability that $A$ is in a specific microstate $s_A$ is as follows: +Let $$c_B(U_B)$$ be the number of $$B$$-microstates with energy $$U_B$$. +Then the probability that $$A$$ is in a specific microstate $$s_A$$ is as follows: $$\begin{aligned} p(s) @@ -30,11 +30,11 @@ $$\begin{aligned} \end{aligned}$$ Then, as for the canonical ensemble, -we assume $U_B \gg U_A$ and $N_B \gg N_A$, -and approximate $\ln{p(s_A)}$ -by Taylor-expanding $\ln{c_B}$ around $U_B = U$ and $N_B = N$. +we assume $$U_B \gg U_A$$ and $$N_B \gg N_A$$, +and approximate $$\ln{p(s_A)}$$ +by Taylor-expanding $$\ln{c_B}$$ around $$U_B = U$$ and $$N_B = N$$. The resulting probability distribution is known as the **Gibbs distribution**, -with $\beta \equiv 1/(kT)$: +with $$\beta \equiv 1/(kT)$$: $$\begin{aligned} \boxed{ @@ -42,7 +42,7 @@ $$\begin{aligned} } \end{aligned}$$ -Where the normalizing **grand partition function** $\mathcal{Z}(\mu, V, T)$ is defined as follows: +Where the normalizing **grand partition function** $$\mathcal{Z}(\mu, V, T)$$ is defined as follows: $$\begin{aligned} \boxed{ @@ -52,9 +52,9 @@ $$\begin{aligned} In contrast to the canonical ensemble, whose [thermodynamic potential](/know/concept/thermodynamic-potential/) -was the Helmholtz free energy $F$, +was the Helmholtz free energy $$F$$, the grand canonical ensemble instead -minimizes the **grand potential** $\Omega$: +minimizes the **grand potential** $$\Omega$$: $$\begin{aligned} \boxed{ @@ -64,8 +64,8 @@ $$\begin{aligned} } \end{aligned}$$ -So $\mathcal{Z} = \exp(- \beta \Omega)$. -This is proven in the same way as for $F$ in the canonical ensemble. +So $$\mathcal{Z} = \exp(- \beta \Omega)$$. +This is proven in the same way as for $$F$$ in the canonical ensemble. |