Richardson extrapolation with operator based interpolation (even, even) points ${\tau }_{\text{Extrapo}}$ (odd, even) points ${\tau }_{\text{Extrapo}}+\frac{7}{48}\left[\frac{1}{24}\left({u}_{{x}^{4}{y}^{2}}+{u}_{{x}^{2}{y}^{4}}\right)-\frac{1}{40}\left({u}_{{x}^{6}}+{u}_{{y}^{6}}\right)\right]{h}^{6}$ (even, odd) points ${\tau }_{\text{Extrapo}}+\frac{7}{48}\left[\frac{1}{24}\left({u}_{{x}^{4}{y}^{2}}+{u}_{{x}^{2}{y}^{4}}\right)-\frac{1}{40}\left({u}_{{x}^{6}}+{u}_{{y}^{6}}\right)\right]{h}^{6}$ (odd, odd) points ${\tau }_{\text{Extrapo}}+\frac{8}{48}\left[\frac{1}{24}\left({u}_{{x}^{4}{y}^{2}}+{u}_{{x}^{2}{y}^{4}}\right)-\frac{1}{40}\left({u}_{{x}^{6}}+{u}_{{y}^{6}}\right)\right]{h}^{6}$ Richardson extrapolation with multiple coarse grid computation (even, even) points ${\tau }_{\text{Extrapo}}$ (odd, even) points ${\tau }_{\text{Extrapo}}+\frac{1}{12}\left\{4×\frac{1}{24}\left({u}_{{x}^{4}{y}^{2}}+{u}_{{x}^{2}{y}^{4}}\right)-\frac{1}{40}\left({u}_{{x}^{6}}+16×{u}_{{y}^{6}}\right)\right\}{h}^{6}$ (even, odd) points ${\tau }_{\text{Extrapo}}+\frac{1}{12}\left\{4×\frac{1}{24}\left({u}_{{x}^{4}{y}^{2}}+{u}_{{x}^{2}{y}^{4}}\right)-\frac{1}{40}\left(16×{u}_{{x}^{6}}+{u}_{{y}^{6}}\right)\right\}{h}^{6}$ (odd, odd) points $\begin{array}{l}{\tau }_{\text{Extrapo}}+\left\{\frac{1}{30}\left[4×\frac{1}{24}\left({u}_{{x}^{4}{y}^{2}}+{u}_{{x}^{2}{y}^{4}}\right)-\frac{1}{40}\left({u}_{{x}^{6}}+16×{u}_{{y}^{6}}\right)\right]\\ +\frac{1}{30}\left[4×\frac{1}{24}\left({u}_{{x}^{4}{y}^{2}}+{u}_{{x}^{2}{y}^{4}}\right)-\frac{1}{40}\left(16×{u}_{{x}^{6}}+{u}_{{y}^{6}}\right)\right]\\ +\frac{1}{20}\left[\frac{1}{24}\left({u}_{{x}^{4}{y}^{2}}+{u}_{{x}^{2}{y}^{4}}\right)-\frac{1}{40}\left({u}_{{x}^{6}}+{u}_{{y}^{6}}\right)\right]\right\}{h}^{6}\end{array}$ Completed Richardson extrapolation (even, even) points ${\tau }_{\text{Extrapo}}$ (odd, even) points ${\tau }_{\text{Extrapo}}+\left\{\frac{1}{24}{u}_{{x}^{4}{y}^{4}}+\frac{1}{120}\left({u}_{{x}^{6}{y}^{2}}+{u}_{{x}^{2}{y}^{6}}\right)-\frac{1}{120}\left({u}_{{x}^{8}}+{u}_{{y}^{8}}\right)\right\}{h}^{6}$ (even, odd) points ${\tau }_{\text{Extrapo}}+\left\{\frac{1}{24}{u}_{{x}^{4}{y}^{4}}+\frac{1}{120}\left({u}_{{x}^{6}{y}^{2}}+{u}_{{x}^{2}{y}^{6}}\right)-\frac{1}{120}\left({u}_{{x}^{8}}+{u}_{{y}^{8}}\right)\right\}{h}^{6}$ (odd, odd) points ${\tau }_{\text{Extrapo}}+\left\{\frac{1}{24}{u}_{{x}^{4}{y}^{4}}+\frac{1}{120}\left({u}_{{x}^{6}{y}^{2}}+{u}_{{x}^{2}{y}^{6}}\right)-\frac{1}{120}\left({u}_{{x}^{8}}+{u}_{{y}^{8}}\right)\right\}{h}^{6}$