I am trying to fit the following model using rstan. I keep getting divergence warnings but decrease adapt_delta doesn’t fix the problem. Is there a way to reparameterize my code to avoid divergence warnings? Or is there an error in my code that is causing these divergence warnings?

```
data {
int<lower=0> k;
real M[k];
real var[k];
}
parameters {
real c;
real Z0;
real Zm;
real<lower=0> sigma;
}
model {
c ~ uniform(0, 1);
Z0 ~ normal(5, 5);
Zm ~ normal(35, 5);
sigma ~ exponential(0.1);
// Likelihood
for(i in 1:k){
M[i] ~ normal(c*var[i]*(var[i]-Z0)*sqrt(Zm-var[i]), sigma);
}
}
```