# Volatility measure in Diebold-Yilmaz connectedness approach

I am trying to create Diebold-Yilmaz connectedness table for returns and volatilities. When I do it for returns everything works properly (I can reproduce their work actually) but for volatilities I keep getting different results. From what I understand they use something called range-based volatility measure which can be found in (https://www.sas.upenn.edu/~fdiebold/papers/paper75/DY2final.pdf) and their other papers. According to paper (and others), it is calculated as:

$$\sigma^2=0.511(H_t-L_t)^2-0,019[(C_t-O_t)(H_t+L_t-2O_t)-2(H_t-O_t)(Lt-Ot)]-0,383(C_t-Ot)^2$$

Where symbols represents natural logarithms of: $$H_t$$ - high price, $$L_t$$ - low price, $$O_t$$ - open price, $$C_t$$ - close price.

Am I missing something? They don’t mention any other formula for volatility. Is there some other way the calculate volatility that was not directly mentioned?