aihaike
Apr26-11, 02:26 AM
Dear all,
In order to develop in cos in sin terms and then simplify the expression
S=\left(q_{j}\cos\mathbf{k}\centerdot\mathbf{r}_{j }\right)\left(\sum_{j}^{N}q_{j}exp\mathbf{-k}\centerdot\mathbf{r}_{j}\right)-\left(q_{j}\cos\mathbf{-k}\centerdot\mathbf{r}_{j}\right)\left(\sum_{j}^{N }q_{j}exp\mathbf{k}\centerdot\mathbf{r}_{j}\right)
I'd like to put the expression
Q=\sum_{j}^{N}q_{j}exp\mathbf{-k}\centerdot\mathbf{r}_{j}
in a variable.
Does anyone know how to proceed ?
Thanks,
Éric.
In order to develop in cos in sin terms and then simplify the expression
S=\left(q_{j}\cos\mathbf{k}\centerdot\mathbf{r}_{j }\right)\left(\sum_{j}^{N}q_{j}exp\mathbf{-k}\centerdot\mathbf{r}_{j}\right)-\left(q_{j}\cos\mathbf{-k}\centerdot\mathbf{r}_{j}\right)\left(\sum_{j}^{N }q_{j}exp\mathbf{k}\centerdot\mathbf{r}_{j}\right)
I'd like to put the expression
Q=\sum_{j}^{N}q_{j}exp\mathbf{-k}\centerdot\mathbf{r}_{j}
in a variable.
Does anyone know how to proceed ?
Thanks,
Éric.