“…First, we note that the approximation scheme (4) does not temporally discretize the semigroup (e tA ) t∈[0,∞) appearing in (2) and is thus an appropriate modification of the accelerated exponential Euler scheme in Section 3 in Jentzen & Kloeden [21] (cf., e.g., also Section 4 in Jentzen & Kloeden [20] for an overview and e.g., Lord & Tambue [27] and Wang & Qi [35] for further results on accelerated exponential Euler approximations). This lack of discretization of the semigroup in the stochastic integral (2) has been proposed in Jentzen & Kloeden [21] to obtain an approximation scheme which converges under suitable assumptions with a significant higher convergence rate than previously analyzed approximation schemes such as the linear implicit Euler scheme or the exponential Euler scheme (cf., e.g., Theorem 3.1 in Jentzen & Kloeden [21], Theorem 1 in [22], Theorem 3.1 in Wang & Qi [35], and Theorem 3.1 in Qi & Wang [29]). In this article the lack of discretization of the semigroup in the non-stochastic integral in (2) is employed for a different purpose, that is, here this lack of discretization is used to obtain a scheme that inherits an appropriate a priori estimate from the exact solution process of the SPDE (3).…”