X-Git-Url: https://hackdaworld.org/gitweb/?p=lectures%2Flatex.git;a=blobdiff_plain;f=posic%2Fthesis%2Fd_tersoff.tex;h=b031be2f58ecd016152de51b4e26e136c23450aa;hp=ca235358238d6e8b3481b245131216a1605b4aa6;hb=17d5c879c418790a154098e51c524eca183c4d98;hpb=6d1beb256b75bb20d1d5e50ca81ed4da17789daa diff --git a/posic/thesis/d_tersoff.tex b/posic/thesis/d_tersoff.tex index ca23535..b031be2 100644 --- a/posic/thesis/d_tersoff.tex +++ b/posic/thesis/d_tersoff.tex @@ -38,7 +38,7 @@ For a three body potential, if $V_{ij}$ is not equal to $V_{ji}$, the derivative \begin{equation} \nabla_{{\bf r}_i} E = \frac{1}{2} \big[ \sum_j ( \nabla_{{\bf r}_i} V_{ij} + \nabla_{{\bf r}_i} V_{ji} ) + \sum_k \sum_j \nabla_{{\bf r}_i} V_{jk} \big] \textrm{ .} \end{equation} -In the following all the necessary derivatives to calculate $\nabla_{{\bf r}_i} E$ are written down. +In the following, all the necessary derivatives to calculate $\nabla_{{\bf r}_i} E$ are written down. \section[Derivative of $V_{ij}$ with respect to ${r}_i$]{\boldmath Derivative of $V_{ij}$ with respect to ${\bf r}_i$} @@ -138,7 +138,7 @@ are calculated and added in subsequent loops. b_{ij} \nabla_{{\bf r}_j} f_A(r_{ij}) + f_A(r_{ij}) \nabla_{{\bf r}_j} b_{ij} \big] \end{eqnarray} -Using the equality $\nabla_{{\bf r}_i} r_{ij}=-\nabla_{{\bf r}_j} r_{ij}$ +Using the equality $\nabla_{{\bf r}_i} r_{ij}=-\nabla_{{\bf r}_j} r_{ij}$, the following relations are valid: \begin{eqnarray} \nabla_{{\bf r}_j} f_R(r_{ij}) &=& - \nabla_{{\bf r}_i} f_R(r_{ij}) \\