Fixed $n \geq 2$, given $K \in GL(n,Z)$. One can view $K$ is a Gram matrix of Lattice. I also imposed that $K$ is symmetric i.e $K^{T}=K$. We can define the autormophism group of $K$. $Aut(K)=\{ W \in GL(n,Z)|W^TKW=K \}.$ One can see similar question [here](https://mathoverflow.net/questions/381265/matrix-congruence-and-smith-normal-form). I know one can use the [Magma](http://magma.maths.usyd.edu.au/calc/) or [Sage](https://doc.sagemath.org/html/en/reference/modules/sage/modules/free_quadratic_module_integer_symmetric.html) to compute the generator of $Aut(K)$ is $K$ is positive definite (now $Aut(K)$ is finite). But now I want to ask is there a way to compute some element of $Aut(K)$? What I understand is that if $K$ is indefinite, then $Aut(K)$ may be infinite. So I understand why both software can not compute the whole group. But what I just want to know: Is there a way at least compute to some of the element in $Aut(K)$? To be more precious, given $K$ is indefinite, I know that $\pm I \in Aut(K)$. But I want to know some other elements (not need to know all $Aut(K)$, where can I get such algorithm or software? I have searched a lot but I still can not find such one. I will be very appreciative of any comments or ideas.